Air conditioning system and control method thereof

Abstract

The application provides an air conditioning system and a control method thereof, comprising a compressor, an indoor unit, an outdoor unit and a reversing device, the reversing device comprises a first valve, a second valve, a third valve and a fourth valve which are sequentially connected in a ring shape; a pipeline between the first valve and the second valve is communicated with the outdoor unit through a first pipeline, a pipeline between the second valve and the third valve leads to a suction port of the compressor through a second pipeline, a pipeline between the third valve and the fourth valve is communicated with the indoor unit through a third pipeline, and a pipeline between the fourth valve and the first valve leads to a discharge port of the compressor through a fourth pipeline; a first stop valve is arranged on the first pipeline, a second stop valve is arranged on the second pipeline, a third stop valve is arranged on the third pipeline, and a fourth stop valve is arranged on the fourth pipeline, so that the technical problems of easy leakage and high maintenance cost of a four-way valve in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of air conditioners, and particularly relates to an air conditioner system and a control method thereof. BACKGROUND

[0002] The industry usually adopts a four-way valve as a reversing component of an air conditioner system to switch between cooling and heating modes and realize the conduction of refrigerant in different operating modes. The four-way valve reversing scheme has the advantage that only one valve is needed to realize mode reversing. However, the four-way valve reversing must be implemented within a specific pressure range, otherwise it is easy to fail to reverse. In addition, the four-way valve is prone to seal leakage after long-term use, and the slider position cannot reach the designed position, which further leads to internal leakage of the four-way valve, air mixing protection, and damage to the unit. In addition, the four-way valve has a high cost, and when it is damaged, the refrigerant needs to be recovered, the maintenance time is long, and the maintenance cost is high.

[0003] Therefore, it is urgent to solve the problems of easy leakage and high maintenance cost of the existing four-way valve. SUMMARY

[0004] Therefore, the present application provides an air conditioner system and a control method thereof, which can solve the technical problems of easy leakage and high maintenance cost of the four-way valve in the prior art.

[0005] The air conditioner system provided by the present application comprises a compressor, an indoor unit, an outdoor unit and a reversing device, wherein the reversing device comprises a first valve, a second valve, a third valve and a fourth valve which are sequentially connected in a ring shape.

[0006] The pipeline between the first valve and the second valve is communicated with the outdoor unit through a first pipeline, the pipeline between the second valve and the third valve is communicated with the suction port of the compressor through a second pipeline, the pipeline between the third valve and the fourth valve is communicated with the indoor unit through a third pipeline, and the pipeline between the fourth valve and the first valve is communicated with the discharge port of the compressor through a fourth pipeline. A first shut-off valve is arranged on the first pipeline, a second shut-off valve is arranged on the second pipeline, a third shut-off valve is arranged on the third pipeline, and a fourth shut-off valve is arranged on the fourth pipeline.

[0007] In some embodiments, the outdoor unit and the indoor unit are communicated through a fifth pipeline, a refrigerant branch is arranged on the fifth pipeline, the refrigerant branch is communicated with the second pipeline, a supercooling valve is arranged on the refrigerant branch, the refrigerant branch between the supercooling valve and the second pipeline is a heat exchange pipeline, and the heat exchange pipeline and the fifth pipeline are thermally coupled through a cold filter.

[0008] In some embodiments, the refrigerant branch intersects with the fifth pipeline at a branch port, a pipeline between the branch port and the outdoor unit is a fifth sub-pipeline, and the heat exchange pipeline and the fifth sub-pipeline are thermally coupled through the subcooling device.

[0009] The application also provides a control method of an air conditioning system, the control method being used for controlling the air conditioning system described above; the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are all manually controlled valves and are in a normally open state; the control method comprises a maintenance method, a heating method, a refrigeration method and a starting method.

[0010] In some embodiments, the maintenance method comprises: controlling the first stop valve, the second stop valve, the third stop valve and the fourth stop valve to be closed.

[0011] In some embodiments, the heating method comprises: controlling the first valve and the third valve to be closed, and controlling the second valve and the fourth valve to be opened.

[0012] The refrigeration method comprises: controlling the second valve and the fourth valve to be closed, and controlling the first valve and the third valve to be opened.

[0013] In some embodiments, the starting method comprises a first equalization method, and the first equalization method comprises:

[0014] Step one, starting the air conditioning system;

[0015] Step two, controlling the first valve, the second valve, the third valve and the fourth valve to be all opened and to be kept for a first preset time length;

[0016] Step three, judging whether the air conditioning system executes a refrigeration mode or a heating mode, when the air conditioning system executes the refrigeration mode, controlling the second valve and the fourth valve to be closed; when the air conditioning system executes the heating mode, controlling the first valve and the third valve to be closed;

[0017] Step four, controlling the compressor to be started.

[0018] In some embodiments, the starting method comprises a second equalization method, and the second equalization method comprises:

[0019] Step one, starting the air conditioning system;

[0020] Step two, determine whether the air conditioning system executes the cooling mode or the heating mode, when the air conditioning system executes the cooling mode, control the second valve to close, control the first valve, the third valve, the fourth valve to open, and continue for a second preset time; when the air conditioning system executes the heating mode, control the third valve to close, control the first valve, the second valve, the fourth valve to open, and continue for a second preset time;

[0021] Step three, when the air conditioning system executes the cooling mode, control the fourth valve to close; when the air conditioning system executes the heating mode, control the first valve to close;

[0022] Step four, control the compressor to start.

[0023] In some embodiments, the starting method includes a pressurization method, and the pressurization method includes:

[0024] Step one, determine whether the air conditioning system is heating or cooling, execute step two when the air conditioning system is cooling; execute step five when the air conditioning system is heating;

[0025] Step two, continuously determine whether the suction side pressure P 13 of the compressor is lower than a first preset pressure P 11 , when P 13 <P 11 , execute step three;

[0026] Step three, first control the fourth valve to open and continue for a third preset time, then control the fourth valve to close and continue for a seventh preset time, and execute step four;

[0027] Step four, continuously determine whether the suction side pressure P 13 of the compressor is lower than a second preset pressure P 11 +10℃, execute step three; when P 13 ≥P 11 +10℃, execute step two;

[0028] Step five, continuously determine whether the suction side pressure P 14 of the compressor is lower than a second preset pressure P 12 , when P 14 <P 12 , execute step six;

[0029] Step six, first control the first valve to open and continue for a fourth preset time, then control the first valve to close and continue for an eighth preset time, and execute step seven;

[0030] Step seven, continuously determine whether the suction side pressure P 14 of the compressor is lower than a second preset pressure P 12 +10℃, execute step six; when P 11 ≥P 12 +10℃, execute step five.

[0031] In some embodiments, the startup method includes a decompression method, the decompression method comprising:

[0032] Step 1: Determine whether the air conditioning system is heating or cooling. If the air conditioning system is cooling, proceed to Step 2; if the air conditioning system is heating, proceed to Step 5.

[0033] Step 2: Continuously monitor the compressor's discharge side pressure P. 23 Is it higher than the third preset pressure P? 21 When P 23 >P 21 Then, proceed to step three;

[0034] Step 3: First, control the fourth valve to open and continue for a fifth preset time, then control the fourth valve to close and continue for a ninth preset time, and then execute Step 4;

[0035] Step 4, when P 23 >P 21 At -10℃, proceed to step three, when P 23 ≤P 21 At -10℃, proceed to step two;

[0036] Step 5: Continuously monitor the compressor's suction side pressure P. 24 Is it lower than the fourth preset pressure P? 22 When P 24 >P 22 Then proceed to step six;

[0037] Step 6: First, control the first valve to open and continue for a sixth preset time, then control the first valve to close and continue for a tenth preset time, and then execute Step 7;

[0038] Step 7, when P 24 >P 22 At -10℃, proceed to step six, when P 24 ≤P 22 At -10℃, proceed to step five.

[0039] In some embodiments, when obtaining P 13 During the eleventh preset time period, multiple inspiratory pressure values, P, are acquired. 13 It is the average of multiple pressure values;

[0040] When P is obtained 14 During the eleventh preset time period, multiple inspiratory pressure values, P, are acquired. 14 It is the average of multiple pressure values;

[0041] When P is obtained 23 During the eleventh preset time period, multiple inspiratory pressure values, P, are acquired. 23is an average of the plurality of pressure values;

[0042] When P 24 is acquired, a plurality of suction side pressure values, P 24 is acquired within an eleventh preset time length, and P

[0043] In some embodiments, the control method further comprises an oil return method and a defrosting method, both of which are the same as the refrigeration method.

[0044] Compared with the prior art through the four-way valve, the reversing device of the present application not only can more agilely realize the flow direction of the refrigerant in the air conditioning system to achieve the switching between the refrigeration and the heating of the air conditioner, but also can realize the pressure reduction start of the air conditioning system when it is turned on, and realize the technical effect of reducing the pressure on the high-pressure side (the discharge side of the compressor) and increasing the pressure on the low-pressure side (the suction side of the compressor) during the working process of the air conditioning system; without the need for additional bypass pressure regulating pipelines and bypass pressure regulating valves, the cost is reduced. When the reversing device needs to be repaired, the first stop valve, the second stop valve, the third stop valve and the fourth stop valve can be closed, without the need for recycling the refrigerant of the air conditioning system. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. The drawings in the following description are only exemplary, and those skilled in the art can also obtain other implementation drawings according to the provided drawings without paying creative labor.

[0046] Figure 1 is a schematic diagram of an air conditioning system of an embodiment of the present application;

[0047] Figure 2 is an enlarged view of A in Figure 1

[0048] Figure 3 is a schematic diagram of the flow direction of the refrigerant at the reversing device during refrigeration of an embodiment of the present application;

[0049] Figure 4 is a schematic diagram of the flow direction of the refrigerant at the reversing device during heating of an embodiment of the present application;

[0050] Figure 5 is a schematic diagram of the starting method when the air conditioning system is turned on of an embodiment of the present application;

[0051] Figure 6 is a control schematic diagram when the pressure on the low-pressure side is increased of an embodiment of the present application;

[0052] ​Figure 7 This is a schematic diagram illustrating the control when the high-pressure side pressure decreases according to an embodiment of the present invention;

[0053] The attached figures are labeled as follows:

[0054] 1. Compressor; 2. Indoor unit; 3. Outdoor unit; 401. First valve; 402. Second valve; 403. Third valve; 404. Fourth valve; 501. First shut-off valve; 502. Second shut-off valve; 503. Third shut-off valve; 504. Fourth shut-off valve; 601. First pipeline; 602. Second pipeline; 603. Third pipeline; 604. Fourth pipeline; 605. Fifth pipeline; 7. Refrigerant branch; 701. Heat exchange pipeline; 702. Subcooler; 703. Distribution port; 704. Subcooling valve; 705. Oil separator 706. Oil return valve; 707. Defrosting temperature sensor; 708. Ambient temperature sensor; 709. Heating EEV; 801. IPM heat dissipation; 802. Subcooled air outlet temperature sensor; 803. Subcooler solenoid valve; 804. Vapor separator inlet temperature sensor; 805. Low pressure sensor; 806. Vapor separator outlet temperature sensor; 807. Vapor separator; 808. Liquid pipe; 809. Gas pipe; 901. Exhaust side; 902. Intake side; 903. High pressure switch; 904. Exhaust temperature sensor; 905. Top of housing temperature sensor; 906. High pressure sensor. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0057] For purposes of the description hereinafter, spatially relative terms, such as "above", "below", "up", "down", "between", "within", "left", "right", "rear", "front", "upper", "lower", "horizontal", "vertical", "above", "below", "top", "bottom", "under", and the like, can be used for ease of description to describe one element's or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described is turned over, elements described as "above" other elements or features would then be oriented "below" the other elements or features. Thus, the exemplary term "above" can encompass both an orientation that is above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. The terms "first", "second", "third", etc., do not necessarily indicate an order or ranking of importance, but rather are used to distinguish one component from another, and are not otherwise intended to refer to magnitude, duration, or intensity, or other parameter or characteristic of the component.

[0058] In addition, it should be noted that the use of "first", "second", and the like words of distinction do not have a special meaning and are used only to distinguish between the corresponding parts, and therefore cannot be understood as limiting the scope of protection of the present application.

[0059] The air conditioning industry usually uses a four-way valve as an air conditioning system reversing component to switch between cooling and heating modes and to realize the conduction of refrigerant in different operating modes. The four-way valve reversing scheme has the advantage that only one valve is needed to realize mode reversing. However, the four-way valve reversing must be implemented within a specific pressure range, otherwise it is easy to fail to reverse. In addition, the four-way valve is prone to seal failure after long-term use, and the slider position cannot reach the designed position, which further leads to internal leakage of the four-way valve, air mixing protection, and damage to the unit. In addition, when the air conditioner compressor starts, in order to avoid the pressure difference between the exhaust end and the suction section (high and low pressure ends) being too large and causing the start to fail, the air bypass is usually performed at startup (before the compressor starts) to balance the pressure on both sides of the compressor (the exhaust side and the suction side), and then the start is performed. In addition, during operation, the low pressure side pressure is too low and the high pressure side pressure is too high, and the compressor can be damaged. The conventional air conditioner also balances the pressure on both ends through air bypass. The prior art usually additionally configures an air bypass valve and a copper pipe to realize air bypass, which has a high cost.

[0060] To solve the above technical problems, with reference to the accompanying drawings Figures 1-4 The application discloses an air conditioning system, comprising a compressor 1, an indoor unit 2, an outdoor unit 3 and a reversing device, wherein the reversing device comprises a first valve 401, a second valve 402, a third valve 403 and a fourth valve 404 which are sequentially connected in series to form a ring shape.

[0061] The pipeline between the first valve 401 and the second valve 402 is communicated with the outdoor unit 3 through a first pipeline 601, the pipeline between the second valve 402 and the third valve 403 is communicated with the suction port of the compressor 1 through a second pipeline 602, the pipeline between the third valve 403 and the fourth valve 404 is communicated with the indoor unit 2 through a third pipeline 603, and the pipeline between the fourth valve 404 and the first valve 401 is communicated with the discharge port of the compressor 1 through a fourth pipeline 604; the first pipeline 601 is provided with a first stop valve 501, the second pipeline 602 is provided with a second stop valve 502, the third pipeline 603 is provided with a third stop valve 503, and the fourth pipeline 604 is provided with a fourth stop valve 504.

[0062] By replacing the four-way valve in the prior art with the reversing device of the present application (the reversing device includes a first valve 401, a second valve 402, a third valve 403, a fourth valve 404, and pipeline components sequentially communicated therewith), compared with the prior art through the four-way valve, the reversing device of the present application can not only more agilely achieve the flow direction of the refrigerant in the air conditioning system to switch between the refrigeration and heating of the air conditioner, but also can achieve the technical effect of pressure reduction start of the air conditioning system when it is turned on, and realize the technical effect of pressure reduction on the high-pressure side (the discharge side of the compressor 1) and pressure increase on the low-pressure side (the suction side 902 of the compressor 1) during the working process of the air conditioning system; without the need for additional bypass pressure regulating pipelines and bypass pressure regulating valves, the cost is reduced. When the reversing device needs to be repaired, the first stop valve 501, the second stop valve 502, the third stop valve 503 and the fourth stop valve 504 can be closed, and the refrigerant in the air conditioning system does not need to be recovered. Further, since the first stop valve 501, the second stop valve 502, the third stop valve 503 and the fourth stop valve 504 are all in the open state during the working of the air conditioner, they are only closed during the repair, and the four stop valves can be set as manually controlled valves, so the reliability is improved.

[0063] Compared with the prior art, the first valve 401, the second valve 402, the third valve 403 and the fourth valve 404 of the present application are independently controlled electromagnetic valves in structure, and the air conditioning system has no pressure requirement on the system pressure when switching between refrigeration and heating, and only the four ordinary electromagnetic valves need to be controlled, so the refrigerant leakage problem caused by the requirement of the system pressure (the compressor 1 frequency modulation to a certain frequency) when the prior art air conditioning system switches the working mode of the air conditioning system (switches between the refrigeration mode and the heating mode) will not occur; the reversing device of the present application is designed ingeniously and simply, has better sealing performance, is more reliable in reversing, and is more convenient to maintain.

[0064] The indoor unit 2 comprises an evaporator, and the outdoor unit 3 comprises a condenser, wherein the evaporator and the condenser are named according to their functions in the refrigeration mode of the system. In the refrigeration mode, the heat exchanger of the indoor unit 2 corresponds to the condenser, and the heat exchanger of the outdoor unit 3 corresponds to the evaporator.

[0065] Preferably, as shown in Figure 1 The fifth pipeline 605 is provided with a refrigerant branch 7, which is in communication with the second pipeline 602. The refrigerant branch 7 is provided with a supercooling valve 704. The refrigerant branch 7 between the supercooling valve 704 and the second pipeline 602 is a heat exchange pipeline 701, which is thermally coupled with the fifth pipeline 605 through a cold cooler 702.

[0066] By providing the refrigerant branch 7, in the refrigeration mode, part of the refrigerant in the fifth pipeline 605 flows into the refrigerant branch 7, and the temperature of the refrigerant in the heat exchange pipeline 701 is reduced after throttling by the supercooling valve 704. The refrigerant in the heat exchange pipeline 701 is cooled by the supercooling cooler 702 and the refrigerant in the fifth pipeline. In this way, the temperature of the refrigerant entering the evaporator is reduced, and the heat exchange efficiency of the evaporator is improved. The temperature of the refrigerant in the heat exchange pipeline 701 is increased after passing through the supercooling cooler 702, but the temperature is still lower than the suction temperature of the compressor 1. The refrigerant in the heat exchange pipeline 701 reduces the temperature of the refrigerant in the second pipeline 602 after entering the second pipeline 602, reduces the suction temperature of the compressor 1, and improves the suction pressure of the compressor 1, thereby improving the compression efficiency of the compressor 1.

[0067] Preferably, as shown in Figure 1 The refrigerant branch 7 intersects with the fifth pipeline 605 at a flow dividing port 703. The pipeline between the flow dividing port 703 and the outdoor unit 3 is a fifth sub-pipeline. The heat exchange pipeline 701 is thermally coupled with the fifth sub-pipeline through the supercooling cooler 702.

[0068] The heat exchange pipeline 701 exchanges heat with the fifth sub-pipeline. The temperature of the refrigerant in the fifth sub-pipeline is reduced and then divided into two parts. One part enters the refrigerant branch 7, and the other part flows to the evaporator. In this way, the temperature of the refrigerant in the fifth pipeline 605 is reduced. The refrigerant with reduced temperature enters the refrigerant branch 7 again. The temperature of the refrigerant after refrigeration is further reduced after throttling by the cold valve 704, thereby further cooling the fifth pipeline 605. This cycle is repeated until the temperature is balanced. This is conducive to further reducing the temperature of the refrigerant in the fifth pipeline 605 and further reducing the temperature of the refrigerant in the refrigerant branch 7. Accordingly, the temperature of the refrigerant entering the second pipeline 602 from the refrigerant branch 7 is also reduced.

[0069] Further, the opening of the supercooling valve 704 can be adjusted, and the amount of refrigerant entering the second pipeline 602 through the refrigerant branch 7 can be adjusted by adjusting the opening of the supercooling valve 704, so as to adjust the pressure and temperature of the suction side 902 of the compressor 1 and improve the working performance of the compressor 1.

[0070] The air conditioning system further includes other conventional components, such as Figure 1 As shown, the air conditioning system includes: an oil separator 705 arranged at the discharge side 901 of the compressor 1, the oil separator 705 is provided with an oil return pipe, and an oil return valve 706 is arranged on the oil return pipe; the discharge side 901 is further provided with a high-pressure switch 903 and a discharge temperature sensing bag 904, and a shell top temperature sensing bag 905 is arranged on the compressor 1; a high-pressure sensor 906 is arranged on the fourth pipeline 604; a defrosting temperature sensing bag 707 and an environment temperature sensing bag 708 are arranged on the outdoor heat exchanger, and an IPM heat dissipation 801 component and a heating EEV 709 (EEV refers to an electromagnetic valve) are arranged on the pipeline between the outdoor heat exchanger and the supercooler 702; a supercooling gas outlet temperature sensing bag 802 and a supercooler electromagnetic valve 803 are arranged on the heat exchange pipeline 701; a gas separation inlet temperature sensing bag 804 is arranged on the second pipeline 602; a low-pressure sensor 805 is arranged on the pipeline between the supercooler 702 and a gas separator 807; a gas separation outlet temperature sensing bag 806 is arranged on the pipeline between the gas separator 807 and the compressor 1; and two pipelines between the indoor unit 2 and the outdoor unit 3 are a liquid pipe 808 and a gas pipe 809.

[0071] The application further provides a control method of the air conditioning system, the control method is used for controlling the air conditioning system; the first stop valve 501, the second stop valve 502, the third stop valve 503 and the fourth stop valve 504 are all manually controlled valves and are in a normally open state; and the control method comprises: a maintenance method, a heating method, a refrigeration method and a starting method.

[0072] The maintenance method is used when the reversing device of the air conditioning system needs to be maintained; the heating method is used when the air conditioning system is started in a heating mode; the refrigeration method is used when the air conditioning system is started in a refrigeration mode; and the starting method is used when the pressures of the suction side 902 and the discharge side 901 of the compressor 1 need to be adjusted during the starting and running of the air conditioning system, so that the air conditioning system can stably run. The first stop valve 501, the second stop valve 502, the third stop valve 503 and the fourth stop valve 504 are mainly used for controlling the maintenance of the reversing device, the four stop valves are manually controlled valves and are in a normally open state, the objects of automatic control are reduced, the control program and the execution components are simplified, the stable running of the air conditioning system is facilitated, and the cost is reduced.

[0073] Preferably, the maintenance method comprises: controlling the first stop valve 501, the second stop valve 502, the third stop valve 503 and the fourth stop valve 504 to be closed.

[0074] When the first stop valve 501, the second stop valve 502, the third stop valve 503 and the fourth stop valve 504 are closed, the refrigerant cannot enter the first valve 401, the second valve 402, the third valve 403 and the fourth valve 404, so that the first valve 401, the second valve 402, the third valve 403 and the fourth valve 404 can be maintained without the need of recycling the refrigerant in the system before maintenance, thereby improving the maintenance efficiency. After the reversing device is maintained, the four stop valves can be manually opened.

[0075] Preferably, as shown in Figure 4 The heating method comprises: controlling the first valve 401 and the third valve 403 to be closed, and controlling the second valve 402 and the fourth valve 404 to be opened.

[0076] The heating method comprises: controlling the first valve 401 and the third valve 403 to be closed, and controlling the second valve 402 and the fourth valve 404 to be opened. Figure 3 The cooling method comprises: controlling the second valve 402 and the fourth valve 404 to be closed, and controlling the first valve 401 and the third valve 403 to be opened.

[0077] The heating method comprises: controlling the first valve 401 and the third valve 403 to be closed, and controlling the second valve 402 and the fourth valve 404 to be opened. The refrigerant flowing out of the compressor 1 flows through the fourth valve 404, the indoor unit 2, the outdoor unit 3 and the second valve 402 in sequence and then flows back to the compressor 1.

[0078] The cooling method comprises: controlling the second valve 402 and the fourth valve 404 to be closed, and controlling the first valve 401 and the third valve 403 to be opened. The refrigerant flowing out of the compressor 1 flows through the first valve 401, the outdoor unit 3, the indoor unit 2 and the third valve 403 in sequence and then flows back to the compressor 1.

[0079] A throttling device can be further arranged between the outdoor unit 3 and the indoor unit 2, which is not shown here.

[0080] Preferably, as shown in Figure 5 The starting method comprises the first pressure equalization method, and the first pressure equalization method comprises:

[0081] Step one, starting the air conditioning system;

[0082] Step two, controlling the first valve 401, the second valve 402, the third valve 403 and the fourth valve 404 to be opened and maintained for a first preset time length;

[0083] Step three, judging whether the air conditioning system executes the cooling mode or the heating mode. When the air conditioning system executes the cooling mode, the second valve 402 and the fourth valve 404 are controlled to be closed. When the air conditioning system executes the heating mode, the first valve 401 and the third valve 403 are controlled to be closed.

[0084] Step four, control the compressor 1 to start.

[0085] Step one, the air conditioning system is started;

[0086] Step two, control the first valve 401, the second valve 402, the third valve 403 and the fourth valve 404 to be opened and last for a first preset time; at this time, whether heating or cooling, the high-pressure side (the exhaust side 901 of the compressor 1) refrigerant will flow to the low-pressure side (the suction side 902 of the compressor 1) through the reversing device, thereby reducing the pressure difference between the exhaust side 901 and the suction side 902 of the compressor 1, so that the compressor 1 starts under low pressure and light load, which is beneficial to reduce the power consumption of the compressor 1 during startup. The pressure between the high-pressure side and the low-pressure side is basically the same within the first preset time, and the first preset time is set according to experience and can be set to 10 seconds.

[0087] Step three, determine whether the air conditioning system executes the cooling mode or the heating mode; when the air conditioning system executes the cooling mode, control the second valve 402 and the fourth valve 404 to be closed; when the air conditioning system executes the heating mode, control the first valve 401 and the third valve 403 to be closed.

[0088] Step four, the compressor 1 starts.

[0089] In the first equalization method, the four valves are opened at the same time, and the high-pressure side refrigerant can flow to the low-pressure side through the fourth valve 404, the third valve 403, and then the second pipeline 602, or flow to the low-pressure side through the first valve 401, the second valve 402, and then the second pipeline 602. Compared with the second method below, the first preset time is smaller.

[0090] In this application, the pressure of the exhaust side 901 of the compressor 1 is the high pressure of the air conditioning system module, which is generally represented by temperature in actual work compared with the outdoor environment, that is, the saturation temperature value corresponding to the exhaust pressure (also known as the condensation saturation temperature). Similarly, the pressure of the suction side 902 of the compressor 1 is the low pressure of the air conditioning system module, that is, the saturation temperature value corresponding to the suction pressure (also known as the evaporation saturation temperature). The unit of the pressure value in this application is "℃", and the temperature represents the pressure of the system, which is a conventional method in the field of air conditioning systems.

[0091] Preferably, the starting method comprises the second equalization method, and the second equalization method comprises:

[0092] Step one, the air conditioning system is started;

[0093] Step two, determine whether the air conditioning system executes the refrigeration mode or executes the heating mode, when the air conditioning system executes the refrigeration mode, control the second valve 402 to close, control the first valve 401, the third valve 403, the fourth valve 404 to open, and continue for a second preset time length; when the air conditioning system executes the heating mode, control the third valve 403 to close, control the first valve 401, the second valve 402, the fourth valve 404 to open, and continue for a second preset time length;

[0094] Step three, when the air conditioning system executes the refrigeration mode, control the fourth valve 404 to close; when the air conditioning system executes the heating mode, control the first valve 401 to close;

[0095] Step four, control the compressor 1 to start.

[0096] Step one, the air conditioning system starts;

[0097] Step two, determine whether the air conditioning system executes the refrigeration mode or executes the heating mode, when the air conditioning system executes the refrigeration mode, control the second valve 402 to close, control the first valve 401, the third valve 403, the fourth valve 404 to open; High-pressure side refrigerant flows to the low-pressure side in turn through the fourth valve 404, the third valve 403, and the second pipeline 602, thereby reducing the system pressure difference when the compressor 1 starts, so that the compressor 1 starts under light load. When the air conditioning system executes the heating mode, control the third valve 403 to close, control the first valve 401, the second valve 402, and the fourth valve 404 to open, and the high-pressure side refrigerant flows to the low-pressure side in turn through the first valve 401, the second valve 402, and the second pipeline 602, thereby reducing the system pressure difference when the compressor 1 starts (the pressure difference between the suction side 902 and the exhaust side 901 of the compressor 1), so that the compressor 1 starts under light load; Continue for a second preset time length, which can be set to 12 seconds. Compared with method one, the path of the refrigerant flowing from the high-pressure side to the low-pressure side is reduced by one, the speed of the refrigerant flow is slower, and the time length is longer.

[0098] Step three, according to the working mode of the air conditioning system, control the working of the reversing valve, when the air conditioning system executes the refrigeration mode, control the fourth valve 404 to close; when the air conditioning system executes the heating mode, control the first valve 401 to close,

[0099] Step four, the compressor 1 starts, and the refrigerant flowing out of the compressor 1 flows back to the compressor 1 in turn through the first valve 401, the outdoor unit 3, the indoor unit 2, and the third valve 403 when refrigerating; the refrigerant flowing out of the compressor 1 flows back to the compressor 1 in turn through the fourth valve 404, the indoor unit 2, the outdoor unit 3, and the second valve 402 when heating.

[0100] Preferably, as Figure 6As shown, the starting method includes a pressurization method, which includes:

[0101] Step one, determine whether the air conditioning system is heating or cooling, execute step two when the air conditioning system is cooling; execute step five when the air conditioning system is heating;

[0102] Step two, continuously determine whether the suction side 902 pressure P 13 of the compressor 1 is lower than the first preset pressure P 11 ; When P 13 < P 11 , execute step three;

[0103] Step three, first control the fourth valve 404 to open and continue for a third preset time, then control the fourth valve 404 to close and continue for a seventh preset time, execute step four;

[0104] Step four, when P 13 < (P 11 + 10℃), execute step three; when P 13 ≥ (P 11 + 10℃), execute step two;

[0105] Step five, continuously determine whether the suction side 902 pressure P 14 of the compressor 1 is lower than the second preset pressure P 12 ; When P 14 < P 12 , execute step six;

[0106] Step six, first control the first valve 401 to open and continue for a fourth preset time, then control the first valve 401 to close and continue for an eighth preset time, execute step seven;

[0107] Step seven, when P 14 < (P 12 + 10℃), execute step six; when P 11 ≥ (P 12 + 10℃), execute step five.

[0108] The pressurization method is a control method during stable operation of the air conditioning system. The suction side 902 pressure of the compressor 1 being too low will result in insufficient suction of the compressor 1, reducing the working efficiency of the compressor 1. It is necessary to increase the airflow pressure of the suction side 902 of the compressor 1;

[0109] Step one, determine whether the air conditioning system is heating or cooling, execute step two when the air conditioning system is cooling; execute step five when the air conditioning system is heating; when the air conditioning system is cooling and heating, the influence of the suction side 902 pressure on the working efficiency of the compressor 1 is different.

[0110] Step two, continuously determine whether the suction side 902 pressure P13 whether lower than the first preset pressure P 11 , the first preset pressure P 11 is selected between -38℃ and -30℃, when P 13 < P 11 , it indicates that the pressure P 13 on the low pressure side is too low, which is not conducive to suction, and the suction side 902 needs to be pressurized, and step three is executed.

[0111] Step three, first control the fourth valve 404 to open for a third preset time, and then control the fourth valve 404 to close for a seventh preset time. The high-pressure refrigerant discharged by the compressor 1 enters the second pipeline 602 after the fourth valve 404, and then flows to the suction side 902, thereby increasing the pressure of the suction side 902. In order to avoid too much flow of high-pressure side refrigerant directly flowing to the low-pressure side, which affects air conditioning refrigeration, after the fourth valve 404 is opened for a third preset time, the fourth valve 404 is closed, and the high-pressure side refrigerant is no longer used to pressurize the low-pressure side. The third preset time can be set to 10 seconds, and then step four is executed.

[0112] Step four, step four is the judgment of the pressure on the low-pressure side after the fourth valve 404 is opened for a third preset time and then closed for a seventh preset time. The pressure of the suction side 902 of the compressor 1 is judged. When P 13 < (P 11 +10℃), the pressure of the suction side 902 has not yet risen above (P 11 +10℃), and needs to continue to be pressurized, and step three is executed. When P 13 ≥(P 11 +10℃), it indicates that the pressure of the suction side 902 has risen by a certain value and is already higher than the first preset pressure. At this time, after the fourth valve 404 is closed, the air conditioning system can continue to operate for a long time. During the operation of the air conditioning system, the pressure of the suction side 902 will continue to decrease. After the fourth valve 404 is closed, the pressure of the suction side 902 needs to be continuously detected, step two is executed, and the cycle is repeated.

[0113] Step five, continuously judge whether the pressure P 14 of the suction side 902 of the compressor 1 is lower than the second preset pressure P 12 . When P 14 < P 12 , step six is executed. The second preset pressure P 12 is selected between -38℃ and -30℃.

[0114] Step six, first control the first valve 401 to open for a fourth preset time, and then control the first valve 401 to close and continue for an eighth preset time, and then execute step seven.

[0115] Step seven, when P 14 < (P 12when P 11 ≥(P 12 +10℃), step five is executed. The principle of boosting the pressure of the suction side 902 by supplementing air during heating is the same as that during refrigeration, but the value is different. 12 between -38℃ and -30℃, or in other set temperature ranges. The seventh preset time length and the eighth preset time length can be 5 minutes, or can be adjusted according to the actual working environment of the air conditioning system and the working frequency of the compressor 1. For example, when the working frequency of the compressor 1 is high, the seventh preset time length and the eighth preset time length can be set to be shorter, for example, 4 minutes; when the working frequency of the compressor 1 is low, the seventh preset time length and the eighth preset time length can be set to be longer, for example, 6 minutes.

[0116] Preferably, as shown in FIG. 1, the starting method comprises a pressure reduction method, and the pressure reduction method comprises: Figure 7

[0117] Step one, determine whether the air conditioning system is heating or refrigerating. When the air conditioning system is refrigerating, step two is executed; when the air conditioning system is heating, step five is executed.

[0118] Step two, continuously determine whether the pressure P 23 of the discharge side 901 of the compressor 1 is higher than a third preset pressure P 21 When P 23 >P 21 , step three is executed.

[0119] Step three, first control the fourth valve 404 to open and last for a fifth preset time length, and then control the fourth valve 404 to close and last for a ninth preset time length, and then execute step four.

[0120] Step four, when P 23 >(P 21 -10℃), step three is executed; when P 23 ≤(P 21 -10℃), step two is executed.

[0121] Step five, continuously determine whether the pressure P 24 of the suction side 902 of the compressor 1 is lower than a fourth preset pressure P 22 When P 24 >P 22 , step six is executed.

[0122] Step six, first control the first valve 401 to open and last for a sixth preset time length, and then control the first valve 401 to close and last for a tenth preset time length, and then execute step seven.

[0123] Step seven, when P 24 >(P 22 ​When P 24 ≤(P 22 -10℃), step five is executed.

[0124] Step one, determine whether the air conditioning system is heating or cooling. When the air conditioning system is cooling, step two is executed. When the air conditioning system is heating, step five is executed. The judgment criteria for the pressure of the exhaust side 901 of the air conditioning system in cooling and heating are different, and different adjustment steps are executed.

[0125] Step two, continuously determine whether the pressure P 23 of the exhaust side 901 of the compressor 1 is higher than a third preset pressure P 21 . When P 23 >P 21 , the pressure of the exhaust side 901 is too high and needs to be reduced. P 21 is a preset value, which can be set between 55℃ and 60℃, and step three is executed.

[0126] Step three, control the fourth valve 404 to be opened for a fifth preset time. The fourth valve 404 is opened for a certain time, and during this time, the high-pressure side refrigerant passes through the fourth valve 404 into the second pipeline, reducing the pressure of the exhaust side 901 (and also increasing the pressure of the suction side 902). Part of the high-pressure refrigerant enters the first side through the reversing device, reducing the cooling capacity of the indoor unit 2. In order to avoid the cooling capacity of the indoor unit 2 being reduced too much, after the fourth valve 404 is opened for the fifth preset time, the fourth valve 404 is closed and continuously opened for a ninth preset time, and then step four is executed to determine the pressure of the high-pressure side. The fifth preset time can be set to 10 seconds according to experience, and the ninth preset time can be set to 5 minutes.

[0127] Step four, when P 23 >(P 21 -10℃), the pressure of the exhaust side 901 is still high. If the fourth valve 404 is closed at this time, the pressure of the exhaust side 901 will soon be higher than the third preset pressure, so step three is executed. When P 23 ≤(P 21 -10℃), the pressure of the exhaust side 901 is low and much lower than the third preset pressure. At this time, after the fourth valve 404 is closed, the air conditioning system can operate for a long time, but the pressure of the exhaust side 901 will continue to rise, and step two is executed to determine the pressure of the exhaust side 901, and the cycle continues.

[0128] Step five, continuously determine whether the pressure P 24 of the suction side 902 of the compressor 1 is lower than a fourth preset pressure P 22 . When P 24 >P 22 , step six is executed. P 22The preset value can be set between 55℃ and 60℃.

[0129] Step six, first control the first valve 401 to open and last for a sixth preset time, then control the first valve 401 to close and last for a tenth preset time, and execute step seven.

[0130] Step seven, when P 24 > (P 22 -10℃), execute step six, and when P 24 ≤ (P 22 -10℃), execute step five. The pressure reduction logic in heating and cooling is the same, and the specific values are different according to the actual working condition. The suction side 902 is provided with a low-pressure sensor 805, and the exhaust side 901 is provided with a high-pressure sensor 906.

[0131] Preferably, when P 13 is obtained, a plurality of suction side 902 pressure values are obtained within an eleventh preset time, and P 13 is the average of the plurality of pressure values.

[0132] When P 14 is obtained, a plurality of suction side 902 pressure values are obtained within an eleventh preset time, and P 14 is the average of the plurality of pressure values.

[0133] When P 23 is obtained, a plurality of suction side 902 pressure values are obtained within an eleventh preset time, and P 23 is the average of the plurality of pressure values.

[0134] When P 24 is obtained, a plurality of suction side 902 pressure values are obtained within an eleventh preset time, and P 24 is the average of the plurality of pressure values.

[0135] Through the above method, the obtained value is more accurate, and the value error caused by accident is avoided. The eleventh preset time can be set to 1 minute.

[0136] Preferably, the control method further comprises an oil return method and a defrosting method, and the oil return method and the defrosting method are the same as the refrigeration method.

[0137] By making the oil return method and the defrosting method the same as the refrigeration method, the control logic of the air conditioning system is relatively simple, and the work is more stable.

[0138] As can be easily understood by those skilled in the art, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed without conflict.

[0139] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method of an air conditioning system, characterized by, The control method is used for controlling an air conditioning system; the air conditioning system comprises a compressor (1), an indoor unit (2), an outdoor unit (3) and a reversing device, characterized in that the reversing device comprises a first valve (401), a second valve (402), a third valve (403) and a fourth valve (404) which are sequentially connected in a ring shape; A pipeline between the first valve (401) and the second valve (402) is communicated with the outdoor unit (3) through a first pipeline (601), a pipeline between the second valve (402) and the third valve (403) leads to a suction port of the compressor (1) through a second pipeline (602), a pipeline between the third valve (403) and the fourth valve (404) is communicated with the indoor unit (2) through a third pipeline (603), and a pipeline between the fourth valve (404) and the first valve (401) leads to a discharge port of the compressor (1) through a fourth pipeline (604); a first shut-off valve (501) is arranged on the first pipeline (601), a second shut-off valve (502) is arranged on the second pipeline (602), a third shut-off valve (503) is arranged on the third pipeline (603), and a fourth shut-off valve (504) is arranged on the fourth pipeline (604); The first shut-off valve (501), the second shut-off valve (502), the third shut-off valve (503) and the fourth shut-off valve (504) are all manually controlled valves and are in a normally open state; the control method comprises a maintenance method, a heating method, a refrigeration method and a starting method; The starting method comprises an equalizing method one, and the equalizing method one comprises: Step one, starting the air conditioning system; Step two, controlling the first valve (401), the second valve (402), the third valve (403) and the fourth valve (404) to be all opened and to be kept for a first preset time length; Step three, judging whether the air conditioning system executes a refrigeration mode or a heating mode; when the air conditioning system executes the refrigeration mode, controlling the second valve (402) and the fourth valve (404) to be closed; when the air conditioning system executes the heating mode, controlling the first valve (401) and the third valve (403) to be closed; Step four, controlling the compressor (1) to start; The starting method comprises an equalizing method two, and the equalizing method two comprises: Step one, starting the air conditioning system; Step two, judging whether the air conditioning system executes a refrigeration mode or a heating mode; when the air conditioning system executes the refrigeration mode, controlling the second valve (402) to be closed, controlling the first valve (401), the third valve (403) and the fourth valve (404) to be opened and to be kept for a second preset time length; when the air conditioning system executes the heating mode, controlling the third valve (403) to be closed, controlling the first valve (401), the second valve (402) and the fourth valve (404) to be opened and to be kept for a second preset time length; Step three, when the air conditioning system performs a cooling mode, control the fourth valve (404) to be closed; when the air conditioning system performs a heating mode, control the first valve (401) to be closed; Step four, control the compressor (1) to start.

2. The control method according to claim 1, characterized by, The fifth pipeline (605) is provided with a refrigerant branch (7), and the refrigerant branch (7) communicates with the second pipeline (602); the refrigerant branch (7) is provided with a supercooling valve (704), and the refrigerant branch (7) between the supercooling valve (704) and the second pipeline (602) is a heat exchange pipeline (701), and the heat exchange pipeline (701) and the fifth pipeline (605) are thermally coupled through a cold filter (702).

3. The control method according to claim 2, characterized by, The refrigerant branch (7) intersects with the fifth pipeline (605) at a flow dividing port (703), and the pipeline between the flow dividing port (703) and the outdoor unit (3) is a fifth sub-pipeline, and the heat exchange pipeline (701) and the fifth sub-pipeline are thermally coupled through the supercooling filter (702).

4. The control method according to claim 1, characterized by, The maintenance method comprises: controlling the first stop valve (501), the second stop valve (502), the third stop valve (503) and the fourth stop valve (504) to be closed.

5. The control method according to claim 1, characterized by, The heating method comprises: controlling the first valve (401) and the third valve (403) to be closed, and controlling the second valve (402) and the fourth valve (404) to be opened; The cooling method comprises: controlling the second valve (402) and the fourth valve (404) to be closed, and controlling the first valve (401) and the third valve (403) to be opened.

6. The control method according to claim 1, characterized by, The starting method comprises a pressure increasing method, and the pressure increasing method comprises: Step one, determine whether the air conditioning system is heating or cooling, execute step two when the air conditioning system is cooling; execute step five when the air conditioning system is heating; Step two, continuously judge the suction side (902) pressure P of the compressor (1) 13 whether lower than the first preset pressure P 11 , when P 13 <P 11 , execute step three; Step three, first control the fourth valve (404) to be opened and last for a third preset time length, then control the fourth valve (404) to be closed and last for a seventh preset time length, and execute step four; Step four, when P 13 Step three, when P 11 +10°C, step two is performed; when P 13 Step two, when P 11 +10°C, step one is performed; when P Step five, continuously judge whether the suction side (902) pressure P of the compressor (1) is lower than the second preset pressure P 14 12 When P 14 < P 12 , execute step six;​ Step six, first control the first valve (401) to be opened and last for a fourth preset time length, then control the first valve (401) to be closed and last for an eighth preset time length, and execute step seven; Step seven, when P 14 Step six is performed when P 12 +10°C, step five is performed when P 14 ≥ P 12 +10°C, step five is performed when P 7. The control method according to claim 6, characterized by The starting method comprises a pressure decreasing method, and the pressure decreasing method comprises: Step one, determine whether the air conditioning system is heating or cooling, execute step two when the air conditioning system is cooling; execute step five when the air conditioning system is heating; Step two, continuously judge the exhaust side (901) pressure P of the compressor (1) 23 whether higher than the third preset pressure P 21 , when P 23 > P 21 , execute step three; Step three, first control the fourth valve (404) to be opened and last for a fifth preset time length, then control the fourth valve (404) to be closed and last for a ninth preset time length, and execute step four; Step four, when P 23 > P 21 -10°C, perform step three, when P 23 ≤ P 21 -10°C, perform step two; Step five, continuously judge whether the exhaust side (901) pressure P24 of the compressor (1) is higher than the fourth preset pressure P 22 When P24>P 22 , execute step six; Step six, first control the first valve (401) to be opened and last for a sixth preset time length, then control the first valve (401) to be closed and last for a tenth preset time length, and execute step seven; Step seven, when P 24 > P 22 -10°C, perform step six, when P 24 ≤ P 22 -10°C, perform step five.

8. The control method according to claim 7, characterized by, When P 13 is acquired, a plurality of inspiratory side (902) pressure values, P 13 , are acquired within an eleventh predetermined time duration; and P 13 is an average of the plurality of pressure values. When acquiring P 14 , a plurality of inspiratory side (902) pressure values, P 14 , are acquired within an eleventh preset time length, and P 14 is an average of the plurality of pressure values. When acquiring P 23 , a plurality of exhaust side (901) pressure values, P 23 , are acquired within an eleventh preset time length, and P 23 is an average value of the plurality of pressure values. When P 24 is acquired, a plurality of exhaust-side (901) pressure values, P24, are acquired over a predetermined period of time, and P24 is an average of the plurality of pressure values.

9. The control method according to claim 1, characterized by, The control method further comprises an oil return method and a defrosting method, and the oil return method and the defrosting method are the same as the cooling method.

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