Air conditioning system and control method thereof

Abstract

The invention discloses an air conditioning system and a control method thereof.The air conditioning system comprises an outdoor unit, an indoor heat dissipation tail end, a refrigerant circulation loop, a valve box, an indoor fan, an indoor motor, an indoor temperature sensor and a controller; when the temperature of the indoor environment is set and the difference value between the set temperature and the current temperature of the indoor environment is larger than the first preset temperature, a fan coil heat dissipation mode is started, and a direct expansion heat dissipation tail end heat dissipation mode is started; and when a control instruction for starting the direct-expansion heat dissipation tail end heat dissipation mode is received and the difference value between the set temperature and the current temperature of the indoor environment is not larger than the first preset temperature, the direct-expansion heat dissipation tail end heat dissipation mode is started, the two heating modes of a fan coil and the direct-expansion heat dissipation tail end can be considered, the heating requirements of different customer groups are met, and the heating efficiency is improved. And the problem that the room temperature rises slowly when a direct expansion heat dissipation tail end is adopted for heating is solved, the comfort level of a user is improved, and therefore the user experience is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to an air conditioning system and a control method thereof. Background Art

[0002] Air source heat pumps are popular in the market for their flexibility and high efficiency in heating. In the current heat pump heating market, air source heat pump water machines occupy most of the market. They transfer heat to the water side, and the water is heated and transported to the indoor water heating terminal through a water pump. This type of product has high initial installation costs, frequent water system failures, and difficult operation and maintenance. In addition, the water pump has high power consumption, which seriously hinders the promotion of air source heat pumps in the heating market. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the purpose of the present invention is to provide an air conditioning system and a control method thereof.

[0004] An air conditioning system proposed in the present invention comprises: an outdoor unit, wherein the outdoor unit comprises a compressor and an outdoor heat exchanger, and is used to exchange heat between a refrigerant and outdoor air; an indoor heat dissipation terminal, wherein the indoor heat dissipation terminal is used to exchange heat between the refrigerant and indoor air, and the indoor heat dissipation terminal comprises at least one fan coil unit and at least one direct expansion heat dissipation terminal; a refrigerant circulation loop, wherein the refrigerant circulation loop comprises an air pipe and a liquid pipe, so that the refrigerant circulates in a loop composed of the compressor, the outdoor heat exchanger, a first expansion valve, the indoor heat dissipation terminal and a four-way valve; the first expansion valve is arranged between the outdoor heat exchanger and the indoor heat dissipation terminal, The first expansion valve is used to increase the flow resistance of the refrigerant passing through the first expansion valve when its opening is reduced, and to reduce the flow resistance of the refrigerant passing through the first expansion valve when its opening is increased; a valve box, a first end of the valve box is connected to the air pipe, a second end of the valve box is connected to the liquid pipe, and a third end of the valve box is connected to the indoor heat dissipation terminal, and the valve box is used to switch the heat dissipation mode of the indoor heat dissipation terminal, and the heat dissipation mode includes a fan coil heat dissipation mode and a direct expansion heat dissipation terminal heat dissipation mode; an indoor fan drives the indoor air to pass through the fan coil by rotating to make the refrigerant and Indoor air is heat exchanged; an indoor motor is used to drive the indoor fan; an indoor temperature sensor is used to detect the temperature of the indoor environment; a controller, the controller is configured to: when receiving a control instruction to start the direct expansion heat dissipation terminal heat dissipation mode, and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, control the indoor heat dissipation terminal to enter the fan coil heat dissipation mode through the valve box to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches a first preset time, control the indoor heat dissipation terminal to enter the direct expansion heat dissipation terminal heat dissipation mode through the valve box, so as to dissipate heat through the direct expansion heat dissipation terminal; when receiving a control instruction to start the direct expansion heat dissipation terminal heat dissipation mode, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, control the indoor heat dissipation terminal to enter the direct expansion heat dissipation terminal heat dissipation mode through the valve box, so as to dissipate heat through the direct expansion heat dissipation terminal.

[0005] In addition, the air conditioning system according to the embodiment of the present invention may also have the following additional technical features:

[0006] Further, the valve box includes: at least one first solenoid valve and at least one second expansion valve, at least one second solenoid valve and at least one third expansion valve; wherein, the first solenoid valve is connected between the air pipe and the fan coil, and the second expansion valve is connected between the liquid pipe and the fan coil; when the first solenoid valve and the second expansion valve are both in an open state, the refrigerant flowing through the fan coil performs heat exchange with the indoor air, so that the indoor heat dissipation terminal enters the fan coil heat dissipation mode; the second solenoid valve is connected between the air pipe and the direct expansion heat dissipation terminal, and the third expansion valve is connected between the liquid pipe and the direct expansion heat dissipation terminal; when the second solenoid valve and the third expansion valve are both in an open state, the refrigerant flowing through the direct expansion heat dissipation terminal performs heat exchange with the indoor air, so that the indoor heat dissipation terminal enters the direct expansion heat dissipation terminal heat dissipation mode.

[0007] Furthermore, after controlling the indoor heat dissipation terminal to enter the direct expansion heat dissipation terminal heat dissipation mode through the valve box, the controller is also configured to: determine whether the compressor is in a preset operating condition, and when it is determined that the compressor is in the preset operating condition, control the operating frequency of the compressor, the speed of the indoor motor and at least one of the first solenoid valves according to the current operating frequency of the compressor and the current temperature of the indoor environment; when it is determined that the compressor is not in the preset operating condition, control the operating frequency of the compressor according to the current operating frequency of the compressor and the current temperature of the indoor environment.

[0008] Further, when it is determined that the compressor is in the preset operating condition, the operating frequency of the compressor, the speed of the indoor motor and at least one of the first solenoid valves are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment. The controller is specifically configured as follows: when the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than a second preset temperature, the operating frequency of the compressor is controlled to remain at the current operating frequency, the speed of the indoor motor is controlled to be zero, and all of the first solenoid valves are controlled to be closed; when the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, the operating frequency of the compressor is controlled to be reduced by a first preset frequency, the speed of the indoor motor is controlled to be zero, and all of the first solenoid valves are controlled to be closed; when the set temperature When the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor has not reached the maximum operating frequency, at least one of the first solenoid valves is controlled to open, and the speed of the indoor motor is controlled to be the lowest speed. After a second preset time, all of the first solenoid valves are controlled to close, and the speed of the indoor motor is controlled to be zero. Thereafter, whether to return to execute the step of determining whether the compressor is in the preset operating state is determined based on the number of first solenoid valves controlled to open. When the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to remain at the maximum operating frequency, the speed of the indoor motor is controlled to be zero, and all of the first solenoid valves are controlled to close.

[0009] Further, when it is determined that the compressor does not appear in the preset operating condition, when the operating frequency of the compressor is controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment, the controller is specifically configured as follows: when the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than the second preset temperature, the operating frequency of the compressor is controlled to remain at the current operating frequency; when the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, the operating frequency of the compressor is controlled to decrease by a second preset frequency; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor does not reach the maximum operating frequency, the operating frequency of the compressor is controlled to increase by a third preset frequency, and the step of determining whether the compressor appears in the preset operating condition is returned; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to remain at the maximum operating frequency.

[0010] Furthermore, whether to return to execute the step of determining whether the compressor is in the preset operating condition is determined based on the number of times the first solenoid valve is controlled to open. The controller is specifically configured as follows: when the number of times the first solenoid valve is controlled to open reaches a maximum number, the controller does not return to execute the step of determining whether the compressor is in the preset operating condition; when the number of times the first solenoid valve is controlled to open does not reach the maximum number, the controller returns to execute the step of determining whether the compressor is in the preset operating condition.

[0011] Further, when the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration during which the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches a first preset time, before the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, the controller is also configured to: control the compressor to operate at a frequency lower than the current operating frequency.

[0012] Furthermore, the air-conditioning system also includes a pressure sensor, which is arranged between the four-way valve and the valve box. The pressure sensor is used to detect the refrigerant pressure in the air pipe. When judging whether the compressor is in a preset operating condition, the controller is specifically configured as follows: when the pressure value detected by the pressure sensor is greater than the preset pressure value, it is determined that the compressor is in a preset operating condition; when the pressure value detected by the pressure sensor is not greater than the preset pressure value, it is determined that the compressor is not in the preset operating condition.

[0013] Furthermore, the direct expansion heat dissipation terminal includes a direct expansion radiator and / or a direct expansion floor heating coil.

[0014] According to an air conditioning system of an embodiment of the present invention, the air conditioning system includes: an outdoor unit, an indoor heat dissipation terminal, a refrigerant circulation loop, a valve box, an indoor fan, an indoor motor, an indoor temperature sensor and a controller. The outdoor unit includes a compressor and an outdoor heat exchanger, which are used to exchange heat between the refrigerant and the outdoor air; the indoor heat dissipation terminal is used to exchange heat between the refrigerant and the indoor air, and the indoor heat dissipation terminal includes at least one fan coil unit and at least one direct expansion heat dissipation terminal; the refrigerant circulation loop includes an air pipe and a liquid pipe, so that the refrigerant circulates in a loop composed of a compressor, an outdoor heat exchanger, a first expansion valve, an indoor heat dissipation terminal and a four-way valve; the first expansion valve is arranged between the outdoor heat exchanger and the indoor heat dissipation terminal, and the first expansion valve is used to reduce the amount of refrigerant passing through the first expansion valve when its opening is reduced. The flow resistance increases, and when the opening increases, the flow resistance of the refrigerant passing through the first expansion valve decreases; the first end of the valve box is connected to the air pipe, the second end of the valve box is connected to the liquid pipe, and the third end of the valve box is connected to the indoor heat dissipation terminal. The valve box is used to switch the heat dissipation mode of the indoor heat dissipation terminal, and the heat dissipation mode includes a fan coil heat dissipation mode and a direct expansion heat dissipation terminal heat dissipation mode; the indoor fan drives the indoor air through the fan coil by rotation, so that the refrigerant and the indoor air exchange heat; the indoor motor is used to drive the indoor fan; the indoor temperature sensor is used to detect the temperature of the indoor environment; control The controller is configured as follows: when a control instruction for starting a direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, the indoor cooling terminal is controlled by the valve box to enter a fan coil cooling mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment being not greater than the first preset temperature reaches a first preset time, the indoor cooling terminal is controlled by the valve box to enter a direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal; when a control instruction for starting a direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter a direct expansion cooling terminal cooling mode, which can take into account both fan coil and direct expansion cooling terminal heating methods, meet the heating needs of different customer groups, and solve the problem of slow room temperature increase when using direct expansion cooling terminals for heating, thereby improving user comfort and thus improving user experience.Furthermore, after the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, it is determined whether the compressor is in a preset operating state. When it is determined that the compressor is in a preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment. The refrigerant circulation volume of the air-conditioning system can be adaptively adjusted to solve the problem of excessive refrigerant in the air-conditioning system causing the compressor frequency to be limited, reduced or even protected, while improving the energy efficiency of the system to achieve the purpose of energy-saving operation.

[0015] In view of the above-mentioned problems, the present invention further proposes a control method for an air-conditioning system, which is used for an air-conditioning system as described in any of the above-mentioned embodiments, and the method comprises the following steps: when a control instruction for starting a heat dissipation mode of a direct expansion heat dissipation terminal is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, the indoor heat dissipation terminal is controlled by a valve box to enter a fan coil heat dissipation mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration for which the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches a first preset time, the indoor heat dissipation terminal is controlled by the valve box to enter the heat dissipation mode of the direct expansion heat dissipation terminal to dissipate heat through the direct expansion heat dissipation terminal; when a control instruction for starting the heat dissipation mode of the direct expansion heat dissipation terminal is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor heat dissipation terminal is controlled by the valve box to enter the heat dissipation mode of the direct expansion heat dissipation terminal to dissipate heat through the direct expansion heat dissipation terminal.

[0016] According to the control method of the air conditioner of the embodiment of the present invention, when a control instruction for starting the direct expansion cooling terminal cooling mode is received and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the fan coil cooling mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment being not greater than the first preset temperature reaches a first preset time, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal, and when a control instruction for starting the direct expansion cooling terminal cooling mode is received and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode, which can take into account both the fan coil and direct expansion cooling terminal heating methods, meet the heating needs of different customer groups, and solve the problem of slow room temperature increase when using the direct expansion cooling terminal for heating, thereby improving the user's comfort and thus improving the user experience. Furthermore, after the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, it is determined whether the compressor is in a preset operating state. When it is determined that the compressor is in a preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment. The refrigerant circulation volume of the air-conditioning system can be adaptively adjusted to solve the problem of excessive refrigerant in the air-conditioning system causing the compressor frequency to be limited, reduced or even protected, while improving the energy efficiency of the system to achieve the purpose of energy-saving operation.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a schematic structural diagram of an air conditioning system according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the hardware structure of a controller according to an embodiment of the present invention;

[0021] Figure 3 is a schematic structural diagram of a valve box according to an embodiment of the present invention;

[0022] Figure 4It is a flow chart of controlling the operating frequency of the compressor, the speed of the indoor motor and the first solenoid valve according to the current operating frequency of the compressor and the current temperature of the indoor environment when it is determined that the compressor is in a preset operating state according to one embodiment of the present invention;

[0023] Figure 5 It is a flow chart of controlling the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve according to the current operating frequency of the compressor and the current temperature of the indoor environment when it is determined that the compressor is in a preset operating state according to one embodiment of the present invention;

[0024] Figure 6 It is a flowchart of controlling the operating frequency of the compressor according to the current operating frequency of the compressor and the current temperature of the indoor environment when it is determined that the compressor is not in a preset operating state according to an embodiment of the present invention;

[0025] Figure 7 is a flowchart of determining whether to return to the step of determining whether the compressor is in a preset working state according to the number of times the first solenoid valve is controlled to be opened according to another embodiment of the present invention;

[0026] Figure 8 is a flow chart of a method for controlling an air conditioning system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Reference below Figure 1-Figure 8 An air conditioning system and a control method thereof according to an embodiment of the present invention are described.

[0032] Figure 1 Schematic diagram of the structure of an air conditioning system according to an embodiment of the present invention. Figure 1As shown, the air conditioning system includes: an outdoor unit 11, an indoor heat dissipation terminal 12, a refrigerant circulation loop (not shown in the figure), a valve box 14, an indoor fan (not shown in the figure), an indoor motor (not shown in the figure), an indoor temperature sensor 102 and a controller (not shown in the figure). Among them, the outdoor unit 11 includes a compressor 1 and an outdoor heat exchanger 4, which are used to exchange heat between the refrigerant and the outdoor air; the indoor heat dissipation terminal 12 is used to exchange heat between the refrigerant and the indoor air, and the indoor heat dissipation terminal 12 includes at least one fan coil 100 and at least one direct expansion heat dissipation terminal, and the direct expansion heat dissipation terminal includes a direct expansion radiator 110 and / or a direct expansion floor heating coil 120; the refrigerant circulation loop includes an air pipe 91 and a liquid pipe 92, so that the refrigerant circulates in the loop composed of the compressor 1, the outdoor heat exchanger 4, the first expansion valve 7, the indoor heat dissipation terminal 12 and the four-way valve 3; the first expansion The valve 7 is arranged between the outdoor heat exchanger 4 and the indoor heat dissipation terminal 12. The first expansion valve 7 is used to increase the flow resistance of the refrigerant passing through the first expansion valve 7 when the opening degree thereof is reduced, and to reduce the flow resistance of the refrigerant passing through the first expansion valve 7 when the opening degree thereof is increased. The first end of the valve box 14 is connected to the air pipe 91, the second end of the valve box 14 is connected to the liquid pipe 92, and the third end of the valve box 14 is connected to the indoor heat dissipation terminal 12. The valve box 14 is used to switch the heat dissipation mode of the indoor heat dissipation terminal 12, and the heat dissipation mode includes one of the fan coil heat dissipation mode and the direct expansion heat dissipation terminal heat dissipation mode. The indoor fan rotates The indoor air is driven to pass through the fan coil 100 so that the refrigerant and the indoor air can exchange heat; the indoor motor is used to drive the indoor fan; the indoor temperature sensor 102 is used to detect the temperature of the indoor environment; the controller 71 is configured as follows: when a control instruction to start the direct expansion heat dissipation terminal heat dissipation mode is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, the indoor heat dissipation terminal 12 is controlled by the valve box 14 to enter the fan coil heat dissipation mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches a first preset time, the indoor heat dissipation terminal 12 is controlled by the valve box 14 to enter the direct expansion heat dissipation terminal heat dissipation mode, and heat is dissipated by the direct expansion heat dissipation terminal; when a control instruction to start the direct expansion heat dissipation terminal heat dissipation mode is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor heat dissipation terminal 12 is controlled by the valve box 14 to enter the direct expansion heat dissipation terminal heat dissipation mode to dissipate heat by the direct expansion heat dissipation terminal.

[0033] First combine Figure 1The cooling and heating principles of the air conditioning system of the embodiment of the present invention are described. When the air conditioning system is in heating operation, the exhaust gas of the compressor 1 enters the valve box 14 through the four-way valve 3, and the refrigerant is distributed to the indoor heat dissipation terminal 12 through the valve box 14, so as to dissipate heat to the indoor through the indoor heat dissipation terminal 12. After the refrigerant is condensed from the high-temperature and high-pressure gas state into a liquid state, it is transported to the outdoor unit 11 through the liquid pipe 92, and enters the outdoor heat exchanger 4 through the high-pressure liquid storage tank 8 and the first expansion valve 7. The refrigerant entering the outdoor heat exchanger 4 absorbs heat and changes from a two-phase state to a superheated gas state. It enters the compressor 1 through the four-way valve 3 to inhale, completing the heating cycle. When the air conditioning system is in cooling operation, at least one fan coil 100 performs a refrigeration cycle, and the direct expansion heat dissipation terminal does not participate in the refrigeration cycle. The process of at least one fan coil 100 performing a refrigeration cycle is consistent with the refrigeration process of a traditional split air conditioner, which will not be described in detail here. The embodiment of the present invention mainly describes the control method for the heating operation of the air conditioning system.

[0034] In the embodiments shown in the present application, the controller refers to a device that can generate an operation control signal according to the instruction operation code and the timing signal to instruct the air conditioner to execute the control instruction. For example, in response to receiving a power-on or power-off instruction issued by a user, the controller can execute an operation related to the object selected by the power-on or power-off instruction.

[0035] The present application also provides a hardware structure diagram of a controller, such as Figure 2 As shown, the controller 71 includes a processor 83, and optionally, further includes a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, the memory 82 and the communication interface 84 are connected via a bus 81.

[0036] The processor 83 may be a central processing unit 83 (CPU), a general processor 83, a network processor 83 (NP), a digital signal processor 83 (DSP), a microprocessor 83, a microcontroller 718, a programmable logic device (PLD), or any combination thereof. The processor 83 may also be any other device having a processing function, such as a circuit, a device, or a software module. The processor 83 may also include multiple CPUs, and the processor 83 may be a single-CPU processor 83 or a multi-CPU processor 83. The processor 83 here may refer to one or more devices, circuits, or processing cores for processing data (such as computer program instructions).

[0037] The memory 82 may be a read-only memory 82 (ROM) or other types of static storage devices that can store static information and instructions, a random access memory 82 (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory 82 (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer, and the present embodiment of the application does not impose any restrictions on this. The memory 82 may exist independently or be integrated with the processor 83. Among them, the memory 82 may contain a computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby realizing the control method of the air-conditioning system provided in the embodiment of the present application.

[0038] The communication interface 84 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc. The communication interface 84 can be a module, a circuit, a transceiver or any device that can achieve communication.

[0039] The bus 81 may be a peripheral component interconnect (PCI) bus 81 or an extended industry standard architecture (EISA) bus 81, etc. The bus 81 may be divided into an address bus 81, a data bus 81, a control bus 81, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus 81 or one type of bus 81.

[0040] Specifically, when the air conditioning system of the embodiment of the present invention is in heating operation, the set temperature and the heat dissipation mode of the indoor radiator terminal 12 are set by the user, including but not limited to setting the indoor temperature and heat dissipation mode through a wired controller or a remote controller. In some embodiments, when the heat dissipation mode is the fan coil heat dissipation mode, the direct expansion heat dissipation terminal heat dissipation mode is in a closed state, and the exhaust of the compressor 1 distributes the refrigerant to at least one fan coil 100 through the valve box 14. The high-temperature and high-pressure refrigerant in at least one fan coil 100 performs forced convection heat exchange with the indoor air, blows out hot air, and transports the heat of the refrigerant to the indoor environment, so as to achieve the purpose of increasing the indoor temperature. This heat dissipation mode has the advantages of rapid heating response and rapid room temperature rise.

[0041] In other embodiments, when the heat dissipation mode is the direct expansion heat dissipation terminal heat dissipation mode, the exhaust gas of the compressor 1 distributes the refrigerant to at least one direct expansion heat dissipation terminal through the valve box 14, and the high-temperature and high-pressure refrigerant in at least one direct expansion heat dissipation terminal performs natural convection heat exchange with the indoor air, which has good thermal comfort, but has the disadvantages of slow response and slow room temperature rise. Therefore, when a control instruction to start the direct expansion heat dissipation terminal heat dissipation mode is received, it is determined whether the temperature difference between the set temperature and the current temperature of the indoor environment is large. When the temperature difference between the set temperature and the current temperature of the indoor environment is large, the indoor radiator terminal 12 is first controlled by the valve box 14 to enter the fan coil heat dissipation mode to quickly increase the indoor temperature. After the temperature difference between the set temperature and the current temperature of the indoor environment is reduced, the indoor radiator terminal 12 is controlled by the valve box 14 to enter the direct expansion cooling terminal cooling mode, and the indoor temperature is further increased by natural convection and radiation. When it is determined that the temperature difference between the set temperature and the current temperature of the indoor environment is small, the indoor radiator terminal 12 is directly controlled by the valve box 14 to enter the direct expansion cooling terminal cooling mode. In this way, the air-conditioning system of the embodiment of the present invention can take into account the fan coil 100 and two heating methods to meet the heating needs of different customer groups, and solve the problem of slow room temperature increase when using direct expansion cooling terminal heating, thereby improving user comfort and thus improving user experience.

[0042] In a specific embodiment, when a control instruction to start the direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than the first preset temperature, it is considered that the temperature difference between the set temperature and the current temperature of the indoor environment is large, and the indoor cooling terminal 12 is controlled by the valve box 14 to enter the fan coil cooling mode, so as to utilize the advantages of the fan coil 100 cooling mode of rapid heating response and rapid room temperature rise, so that the current temperature of the indoor environment is rapidly increased, and the temperature difference between the set temperature and the current temperature of the indoor environment is reduced, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, for example, 5°C, and the duration of the difference between the set temperature and the current temperature of the indoor environment being no greater than 5°C of the first preset temperature reaches a first preset time, for example, 10 seconds. At this time, it is considered that the temperature difference between the set temperature and the current temperature of the indoor environment is small, and then the indoor radiator terminal 12 is controlled by the valve box 14 to enter the direct expansion cooling terminal cooling mode, so as to further increase the indoor temperature through natural convection and radiation, thereby improving the user's comfort. In other embodiments, when a control instruction to start the direct expansion heat dissipation terminal heat dissipation mode is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature of 5°C, it is considered that the temperature difference between the set temperature and the current temperature of the indoor environment is small, and the indoor heat dissipation terminal 12 is controlled by the valve box 14 to directly enter the direct expansion heat dissipation terminal heat dissipation mode, so as to dissipate heat through the direct expansion heat dissipation terminal to improve the user's comfort. It is understandable that the first preset temperature and the first preset time can be pre-set according to actual conditions and stored in the controller 71, which will not be described in detail here.

[0043] In one embodiment of the present invention, Figure 3 As shown, the valve box 14 includes: at least one first solenoid valve 93 or at least one second expansion valve 94, at least one second solenoid valve 95 and at least one third expansion valve 96; wherein the first solenoid valve 93 is connected between the air pipe 91 and the fan coil, and the second expansion valve 94 is connected between the liquid pipe 92 and the fan coil; when the first solenoid valve 93 and the second expansion valve 94 are both in the open state, the refrigerant flowing through the fan coil performs heat exchange with the indoor air, so that the indoor heat dissipation terminal enters the fan coil heat dissipation mode; the second solenoid valve 95 is connected between the air pipe 91 and the direct expansion heat dissipation terminal, and the third expansion valve 96 is connected between the liquid pipe 92 and the direct expansion heat dissipation terminal; when the second solenoid valve 95 and the third expansion valve 96 are both in the open state, the refrigerant flowing through the direct expansion heat dissipation terminal performs heat exchange with the indoor air, so that the indoor heat dissipation terminal enters the direct expansion heat dissipation terminal heat dissipation mode.

[0044] Specifically, if Figure 3As shown, when the heat dissipation mode is the fan coil heat dissipation mode, the first solenoid valve 93 and the second expansion valve 94 connected to the fan coil in the control valve box 14 are opened, and the second solenoid valve 95 and the third expansion valve 96 connected to the direct expansion heat dissipation end are controlled to be closed. At this time, the compressor exhaust enters the valve box 14 through the air pipe 91. Since the first solenoid valve 93 and the second expansion valve 94 are in the open state, the second solenoid valve 95 and the third expansion valve 96 are in the closed state, the high-temperature and high-pressure refrigerant is distributed to at least one fan coil, and the refrigerant flowing through the fan coil performs heat exchange with the indoor air. After the gaseous refrigerant is condensed into liquid, it is transported to the outdoor unit through the liquid pipe 92. When the cooling mode is the direct expansion cooling terminal cooling mode, the second solenoid valve 95 and the third expansion valve 96 connected to the direct expansion cooling terminal in the control valve box 14 are opened, and the first solenoid valve 93 and the second expansion valve 94 connected to the fan coil are controlled to be closed. At this time, the compressor exhaust enters the valve box 14 through the air pipe 91. Since the first solenoid valve 93 and the second expansion valve 94 are in a closed state, the second solenoid valve 95 and the third expansion valve 96 are in an open state, and the high-temperature and high-pressure refrigerant is distributed to at least one direct expansion cooling terminal. The refrigerant flowing through the direct expansion cooling terminal exchanges heat with the indoor air. After the gaseous refrigerant is condensed into liquid, it is transported to the outdoor unit through the liquid pipe 92.

[0045] It is understandable that the direct expansion heat dissipation terminal includes a direct expansion radiator 110 and / or a direct expansion floor heating coil 120. When the air conditioning system includes both direct expansion radiator 110 and direct expansion floor heating coil 120, during the heating process, only one type of direct expansion heat dissipation terminal can be turned on for heating, and two different types of direct expansion heat dissipation terminals cannot be turned on at the same time, that is, the heat dissipation mode of the direct expansion heat dissipation terminal includes a direct expansion radiator heat dissipation mode or a direct expansion floor heating coil heat dissipation mode, and the user can determine which direct expansion heat dissipation terminal to use for heating by selecting the direct expansion radiator heat dissipation mode or the direct expansion floor heating coil heat dissipation mode.

[0046] In one embodiment of the present invention, Figure 4 As shown, after the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, the controller is also configured to: determine whether the compressor is in a preset operating state, and when it is determined that the compressor is in a preset operating state, control the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve according to the current operating frequency of the compressor and the current temperature of the indoor environment; when it is determined that the compressor is not in the preset operating state, control the operating frequency of the compressor according to the current operating frequency of the compressor and the current temperature of the indoor environment.

[0047] Specifically, when the heat dissipation mode is the direct expansion heat dissipation terminal heat dissipation mode, the refrigerant circulation loop may be at risk of excessive refrigerant, resulting in limited compressor frequency increase and reduced system energy efficiency, that is, the compressor may be at risk of high-voltage frequency limitation. The preset operating condition in the embodiment of the present invention is a state in which the compressor is at high-voltage frequency limitation. When it is determined that the compressor has high-voltage frequency limitation, the embodiment of the present invention controls the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve according to the current operating frequency of the compressor and the current temperature of the indoor environment, so as to solve the problem of high-voltage frequency limitation of the compressor caused by excessive refrigerant in the air-conditioning system, so as to further increase the temperature of the indoor environment, improve the operating efficiency of the air-conditioning system, and achieve the purpose of energy-saving operation; when it is determined that the compressor has not had high-voltage frequency limitation, it is only necessary to control the operating frequency of the compressor according to the current operating frequency of the compressor and the current temperature of the indoor environment, and increase the frequency of the compressor according to the normal heating control method to maximize the heating capacity of the air-conditioning system. In this way, when the heat dissipation mode is the direct expansion heat dissipation terminal heat dissipation mode, the embodiment of the present invention can adaptively adjust the refrigerant circulation volume of the air-conditioning system to solve the problem of excessive refrigerant in the air-conditioning system causing the compressor frequency to be limited, reduced or even protected, while improving the energy efficiency of the system to achieve the purpose of energy-saving operation.

[0048] In one embodiment of the present invention, Figure 5 As shown, when it is determined that the compressor is in a preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment. The controller is specifically configured as follows: when the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than a second preset temperature, the operating frequency of the compressor is controlled to remain at the current operating frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed; when the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, the operating frequency of the compressor is controlled to be reduced to the first preset frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed; when the set temperature is less than the indoor temperature, the operating frequency of the compressor is controlled to be reduced to the first preset frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed. When the difference between the current temperature of the environment is greater than the second preset temperature and the current operating frequency of the compressor has not reached the maximum operating frequency, at least one first solenoid valve is controlled to open, and the speed of the indoor motor is controlled to be the lowest speed. After the second preset time, all the first solenoid valves are controlled to be closed, and the speed of the indoor motor is controlled to be zero. Thereafter, based on the number of first solenoid valves controlled to be opened, it is determined whether to return to the step of determining whether the compressor is in a preset operating state; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to remain at the maximum operating frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed.

[0049] Specifically, when it is determined that the compressor has high-voltage frequency limitation, and the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than the second preset temperature, for example, 0.5°C, it is considered that the current temperature of the indoor environment meets the set temperature requirement, and there is no need to further increase the current temperature of the indoor environment by increasing the operating frequency of the compressor, that is, there is no need to solve the high-voltage frequency limitation problem of the compressor. At this time, the operating frequency of the compressor is controlled to remain at the current operating frequency, and the speed of the indoor motor is controlled to be zero to reduce energy consumption, avoid unnecessary air flow, and control all first solenoid valves to be closed, so that the direct expansion heat dissipation terminal heat dissipation mode operates stably. It can be understood that the second preset temperature can be pre-set according to actual conditions and stored in the controller.

[0050] In other implementations, when it is determined that the compressor has high-voltage frequency limitation, and the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature of 0.5°C, it is considered that the temperature of the indoor environment is higher than the set temperature and needs to be cooled down, and there is no need to solve the problem of high-voltage frequency limitation of the compressor. At this time, the operating frequency of the compressor is controlled to be reduced to a first preset frequency, for example, 10HZ, and the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed to quickly reduce the temperature of the indoor environment to make it close to the set temperature. It is understandable that when the operating frequency of the compressor is controlled to be reduced to a first preset frequency, the first preset frequency can be determined according to the difference between the current temperature of the indoor environment and the set temperature, which will not be elaborated here.

[0051] In other implementations, when it is determined that the compressor has high-pressure frequency limitation, and the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature of 0.5°C, and the current operating frequency of the compressor has not reached the maximum operating frequency, it is considered that the temperature of the indoor environment is lower than the set temperature, and it is necessary to further increase the current temperature of the indoor environment by increasing the operating frequency of the compressor so that the temperature of the indoor environment is close to the set temperature, that is, it is necessary to solve the problem of high-pressure frequency limitation of the compressor. At this time, at least one first solenoid valve is controlled to open to store the excess refrigerant in the refrigerant circulation loop into the fan coil unit to avoid the limitation of the compressor frequency increase and ensure the smooth progress of the heating process; further, the speed of the indoor motor is controlled to be the lowest speed so that the refrigerant stored in the fan coil unit changes from gas to liquid quickly, so that more refrigerant can be transmitted to the fan coil unit through the first solenoid valve, and after a second preset time, for example 20 seconds, the first solenoid valve is controlled to close, and the speed of the indoor motor is controlled to be zero to complete the storage of the refrigerant, and then it is determined whether to return to the step of determining whether the compressor has a preset operating state according to the number of first solenoid valves controlled to open. It is understandable that after the second preset time, it is considered that the current temperature of the indoor environment has reached the set temperature requirement, or the current operating frequency of the compressor has reached the maximum operating frequency, and it is no longer necessary to solve the high-pressure frequency limiting problem of the compressor by adjusting the refrigerant circulation volume of the air-conditioning system. Afterwards, since the set temperature may change, the compressor may appear in a high-pressure frequency limiting state again, and the number of openings of the first solenoid valve is limited, that is, the amount of refrigerant stored by the fan coil unit is limited. When the number of openings of the first solenoid valve reaches the maximum and the compressor appears in a high-pressure frequency limiting state again, it is impossible to solve the high-pressure frequency limiting problem of the compressor by adjusting the refrigerant circulation volume of the air-conditioning system. Therefore, it is necessary to determine whether to return to execute the step of determining whether the compressor is in a preset operating state based on the number of openings of the first solenoid valve.

[0052] In other implementations, when it is determined that the compressor has high-voltage frequency limiting, and the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor has reached the maximum operating frequency, it is considered that the air-conditioning system has already exerted its maximum heating capacity at this time, and the current temperature of the indoor environment cannot be further increased by continuing to increase the operating frequency of the compressor, that is, there is no need to solve the problem of high-voltage frequency limiting of the compressor. At this time, the operating frequency of the compressor is controlled to be maintained at the maximum operating frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed, so that the direct expansion heat dissipation terminal heat dissipation mode enters stable operation.

[0053] In one embodiment of the present invention, Figure 6As shown, when it is determined that the compressor does not appear in the preset operating condition, when the operating frequency of the compressor is controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment, the controller is specifically configured as follows: when the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than the second preset temperature, the operating frequency of the compressor is controlled to remain at the current operating frequency; when the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, the operating frequency of the compressor is controlled to decrease by the second preset frequency; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor has not reached the maximum operating frequency, the operating frequency of the compressor is controlled to increase by the third preset frequency, and the step of determining whether the compressor appears in the preset operating condition is returned; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to remain at the maximum operating frequency.

[0054] Specifically, when it is determined that the compressor has not experienced high-voltage frequency limiting, and the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than a second preset temperature, for example, 0.5°C, it is considered that the temperature of the indoor environment has reached the set temperature requirement. At this time, the operating frequency of the compressor is controlled to remain at the current operating frequency, and the direct expansion cooling terminal cooling mode operates stably.

[0055] In other implementations, when it is determined that the compressor does not have high-voltage frequency limiting, and the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, for example, 0.5°C, it is considered that the temperature of the indoor environment is higher than the set temperature and needs to be cooled. At this time, the operating frequency of the compressor is controlled to be reduced by a second preset frequency, for example, 20HZ, so as to quickly reduce the temperature of the indoor environment to make it close to the set temperature. It is understandable that when the operating frequency of the compressor is controlled to be reduced by the second preset frequency, the second preset frequency can be determined according to the difference between the current temperature of the indoor environment and the set temperature, which will not be described in detail here.

[0056] In other implementations, when it is determined that the compressor does not have high-voltage frequency limitation, and the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature of 0.5°C, and the current operating frequency of the compressor has not reached the maximum operating frequency, it is considered that the temperature of the indoor environment is lower than the set temperature, and it is necessary to further increase the current temperature of the indoor environment by increasing the operating frequency of the compressor so that the temperature of the indoor environment is close to the set temperature. At this time, the operating frequency of the compressor is controlled to increase by a third preset frequency, for example, 30HZ. Since the compressor may have a frequency limitation problem due to excessive refrigerant in the refrigerant circulation loop during the frequency increase process, when the operating frequency of the compressor is controlled to increase by the third preset frequency, it is necessary to return to the execution of determining whether the compressor has a high-voltage frequency limitation condition, so that when the compressor has a high-voltage frequency limitation condition, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment, so as to adaptively adjust the refrigerant circulation amount of the air-conditioning system to ensure efficient operation of the system.

[0057] In other implementations, when it is determined that the compressor has not experienced high-voltage frequency limiting, and the difference between the set temperature and the current temperature of the indoor environment is greater than a second preset temperature, and the current operating frequency of the compressor has reached the maximum operating frequency, it is considered that the air-conditioning system has exerted its maximum heating capacity. At this time, the operating frequency of the compressor is controlled to remain at the maximum operating frequency so that the direct expansion cooling terminal cooling mode can enter a stable state.

[0058] In one embodiment of the present invention, Figure 7 As shown, whether to return to execute the step of determining whether the compressor is in a preset operating state is determined based on the number of times the first solenoid valve is controlled to open. The controller is specifically configured as follows: when the number of times the first solenoid valve is controlled to open reaches a maximum number, the controller does not return to execute the step of determining whether the compressor is in a preset operating state; when the number of times the first solenoid valve is controlled to open does not reach the maximum number, the controller returns to execute the step of determining whether the compressor is in a preset operating state.

[0059] Specifically, since there may be more than one fan coil unit, when storing refrigerant in the fan coil unit to avoid the compressor frequency increase being limited, it is necessary to determine whether each fan coil unit is full of refrigerant. When the number of openings of the first solenoid valve is controlled to reach the maximum number, it is considered that the fan coil units have all turned on the refrigerant storage function and can no longer continue to perform the refrigerant storage function. That is, when it is determined that the compressor has high-pressure frequency limitation, it is impossible to solve the high-pressure frequency limitation problem of the compressor by adjusting the refrigerant circulation volume of the air-conditioning system. At this time, the step of determining whether the compressor has a preset operating condition (the compressor has a high-pressure frequency limitation) is not returned to, and the direct expansion heat dissipation terminal heat dissipation mode can be put into stable operation. When the number of openings of the first solenoid valve is controlled not to reach the maximum number, it indicates that the fan coil unit can continue to store refrigerant. At this time, the step of determining whether the compressor has a preset operating condition is returned to execute, so that when the compressor has high-pressure frequency limitation, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment to adjust the temperature of the indoor environment.

[0060] In one embodiment of the present invention, when the difference between the set temperature and the current temperature of the indoor environment is not greater than a first preset temperature, and the duration for which the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches a first preset time, before the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, the controller is also configured to: control the compressor to operate at a frequency lower than the current operating frequency.

[0061] Specifically, as mentioned above, when a control instruction to start the direct expansion heat dissipation terminal heat dissipation mode is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than the first preset temperature, the indoor heat dissipation terminal is first controlled by the valve box to enter the fan coil heat dissipation mode, and when the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches the first preset time, the indoor heat dissipation terminal is then controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode. When the indoor heat dissipation terminal is switched from the fan coil heat dissipation mode to the direct expansion heat dissipation terminal heat dissipation mode, if the compressor enters the direct expansion heat dissipation terminal heat dissipation mode at a higher operating frequency, it will generate greater noise and reduce the service life of the compressor. Therefore, before the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, the compressor needs to be controlled to operate at a frequency lower than the current operating frequency. Preferably, the compressor is controlled to operate at the lowest frequency.

[0062] In one embodiment of the present invention, Figure 1As shown, the air-conditioning system also includes a pressure sensor 9, which is arranged between the four-way valve 3 and the valve box 14. The pressure sensor 9 is used to detect the refrigerant pressure in the air pipe. When judging whether the compressor 1 is in a preset working condition, the controller is specifically configured as follows: when the pressure value detected by the pressure sensor 9 is greater than the preset pressure value, it is determined that the compressor 1 is in a preset working condition; when the pressure value detected by the pressure sensor 9 is not greater than the preset pressure value, it is determined that the compressor 1 is not in the preset working condition.

[0063] Specifically, the refrigerant pressure is one of the indicators of the working state of the compressor 1. By detecting the refrigerant pressure in the air pipe, it can be determined whether the compressor 1 has high-pressure frequency limiting. When the pressure value of the refrigerant in the air pipe detected by the pressure sensor 9 is greater than the preset pressure value, it is considered that the compressor 1 has high-pressure frequency limiting; when the pressure value of the refrigerant in the air pipe detected by the pressure sensor 9 is not greater than the preset pressure value, it is considered that the compressor 1 has not had high-pressure frequency limiting. It can be understood that the preset pressure value is the threshold value for the occurrence of high-pressure frequency limiting in the compressor 1, and the preset pressure value is pre-stored in the controller.

[0064] According to an air conditioning system of an embodiment of the present invention, the air conditioning system includes: an outdoor unit, an indoor heat dissipation terminal, a refrigerant circulation loop, a valve box, an indoor fan, an indoor motor, an indoor temperature sensor and a controller. The outdoor unit includes a compressor and an outdoor heat exchanger, which are used to exchange heat between the refrigerant and the outdoor air; the indoor heat dissipation terminal is used to exchange heat between the refrigerant and the indoor air, and the indoor heat dissipation terminal includes at least one fan coil unit and at least one direct expansion heat dissipation terminal; the refrigerant circulation loop includes an air pipe and a liquid pipe, so that the refrigerant circulates in a loop composed of a compressor, an outdoor heat exchanger, a first expansion valve, an indoor heat dissipation terminal and a four-way valve; the first expansion valve is arranged between the outdoor heat exchanger and the indoor heat dissipation terminal, and the first expansion valve is used to reduce the flow resistance of the refrigerant passing through the first expansion valve when its opening is reduced. The force increases, and when the opening increases, the flow resistance of the refrigerant passing through the first expansion valve is reduced; the first end of the valve box is connected to the air pipe, the second end of the valve box is connected to the liquid pipe, and the third end of the valve box is connected to the indoor heat dissipation terminal. The valve box is used to switch the heat dissipation mode of the indoor heat dissipation terminal, and the heat dissipation mode includes a fan coil heat dissipation mode and a direct expansion heat dissipation terminal heat dissipation mode; the indoor fan drives the indoor air through the fan coil by rotation, so that the refrigerant and the indoor air are heat exchanged; the indoor motor is used to drive the indoor fan; the indoor temperature sensor is used to detect the temperature of the indoor environment; the controller is configured as follows: When a control instruction for starting the direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the fan coil cooling mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment being not greater than the first preset temperature reaches the first preset time, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal; when a control instruction for starting the direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal. This can take into account both fan coil and direct expansion cooling terminals, meet the heating needs of different customer groups, and solve the problem of slow room temperature increase when using direct expansion cooling terminals for heating, thereby improving user comfort and thus improving user experience.Furthermore, after the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, it is determined whether the compressor is in a preset operating state. When it is determined that the compressor is in a preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment. The refrigerant circulation volume of the air-conditioning system can be adaptively adjusted to solve the problem of excessive refrigerant in the air-conditioning system causing the compressor frequency to be limited, reduced or even protected, while improving the energy efficiency of the system to achieve the purpose of energy-saving operation.

[0065] A further embodiment of the present invention also discloses a control method for an air conditioning system, such as Figure 8 As shown, for the air conditioning system as described in any of the above embodiments, the method comprises the following steps:

[0066] Step S1: When a control instruction to start the direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the fan coil cooling mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment being not greater than the first preset temperature reaches a first preset time, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal.

[0067] Step S2: When a control instruction to start the direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal.

[0068] In one embodiment of the present invention, the valve box includes: at least one first solenoid valve and at least one second expansion valve, at least one second solenoid valve and at least one third expansion valve; wherein the first solenoid valve is connected between the air pipe and the fan coil, and the second expansion valve is connected between the liquid pipe and the fan coil; when the first solenoid valve and the second expansion valve are both in an open state, the refrigerant flowing through the fan coil performs heat exchange with the indoor air, so that the indoor heat dissipation terminal enters the fan coil heat dissipation mode; the second solenoid valve is connected between the air pipe and the direct expansion heat dissipation terminal, and the third expansion valve is connected between the liquid pipe and the direct expansion heat dissipation terminal; when the second solenoid valve and the third expansion valve are both in an open state, the refrigerant flowing through the direct expansion heat dissipation terminal performs heat exchange with the indoor air, so that the indoor heat dissipation terminal enters the direct expansion heat dissipation terminal heat dissipation mode.

[0069] In one embodiment of the present invention, after the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, it also includes: judging whether the compressor is in a preset operating state, and when it is judged that the compressor is in a preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment; when it is judged that the compressor is not in the preset operating state, the operating frequency of the compressor is controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment.

[0070] In one embodiment of the present invention, when it is determined that the compressor is in a preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment, including: when the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than a second preset temperature, the operating frequency of the compressor is controlled to remain at the current operating frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed; when the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, the operating frequency of the compressor is controlled to be reduced by the first preset frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed; when the set temperature is greater than the indoor temperature, the operating frequency of the compressor is controlled to be reduced by the first preset frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed. When the difference between the current temperature of the environment is greater than the second preset temperature and the current operating frequency of the compressor has not reached the maximum operating frequency, at least one first solenoid valve is controlled to open, and the speed of the indoor motor is controlled to be the lowest speed. After the second preset time, all the first solenoid valves are controlled to be closed, and the speed of the indoor motor is controlled to be zero. Thereafter, based on the number of first solenoid valves controlled to be opened, it is determined whether to return to the step of determining whether the compressor is in a preset operating state; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to remain at the maximum operating frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed.

[0071] In one embodiment of the present invention, when it is determined that the compressor does not appear in a preset operating condition, the operating frequency of the compressor is controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment, including: when the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than the second preset temperature, the operating frequency of the compressor is controlled to remain at the current operating frequency; when the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, the operating frequency of the compressor is controlled to decrease by the second preset frequency; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor has not reached the maximum operating frequency, the operating frequency of the compressor is controlled to increase by a third preset frequency, and the step of determining whether the compressor appears in a preset operating condition is returned to be executed; when the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to remain at the maximum operating frequency.

[0072] In one embodiment of the present invention, whether to return to execute the step of determining whether the compressor is in a preset operating condition is determined based on the number of times the first solenoid valve is controlled to open, including: when the number of times the first solenoid valve is controlled to open reaches a maximum number, not returning to execute the step of determining whether the compressor is in a preset operating condition; when the number of times the first solenoid valve is controlled to open does not reach the maximum number, returning to execute the step of determining whether the compressor is in a preset operating condition.

[0073] In one embodiment of the present invention, when the difference between the set temperature and the current temperature of the indoor environment is not greater than a first preset temperature, and the duration for which the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches a first preset time, before the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, it also includes: controlling the compressor to operate at a frequency lower than the current operating frequency.

[0074] In one embodiment of the present invention, the air-conditioning system also includes a pressure sensor, which is arranged between the four-way valve and the valve box. The pressure sensor is used to detect the refrigerant pressure in the air pipe and judge whether the compressor is in a preset operating state, including: when the pressure value detected by the pressure sensor is greater than the preset pressure value, it is determined that the compressor is in a preset operating state; when the pressure value detected by the pressure sensor is not greater than the preset pressure value, it is determined that the compressor is not in the preset operating state.

[0075] In one embodiment of the present invention, the direct expansion heat dissipation terminal includes a direct expansion radiator and / or a direct expansion floor heating coil.

[0076] According to the control method of the air-conditioning system of the embodiment of the present invention, when a control instruction for starting the direct expansion cooling terminal cooling mode is received and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the fan coil cooling mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment being not greater than the first preset temperature reaches a first preset time, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal, and when a control instruction for starting the direct expansion cooling terminal cooling mode is received and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode, which can take into account both the fan coil and direct expansion cooling terminal heating methods, meet the heating needs of different customer groups, and solve the problem of slow room temperature increase when using the direct expansion cooling terminal for heating, thereby improving the user's comfort and thus improving the user experience. Furthermore, after the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, it is determined whether the compressor is in a preset operating state. When it is determined that the compressor is in a preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one first solenoid valve are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment. The refrigerant circulation volume of the air-conditioning system can be adaptively adjusted to solve the problem of excessive refrigerant in the air-conditioning system causing the compressor frequency to be limited, reduced or even protected, while improving the energy efficiency of the system to achieve the purpose of energy-saving operation.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0078] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An air conditioning system, characterized in that: include: An outdoor unit, the outdoor unit comprising a compressor and an outdoor heat exchanger, for exchanging heat between the refrigerant and the outdoor air; An indoor heat dissipation terminal, the indoor heat dissipation terminal is used to exchange heat between the refrigerant and the indoor air, and the indoor heat dissipation terminal includes at least one fan coil unit and at least one direct expansion heat dissipation terminal; A refrigerant circulation loop, the refrigerant circulation loop comprising an air pipe and a liquid pipe, so that the refrigerant circulates in a loop consisting of the compressor, the outdoor heat exchanger, the first expansion valve, the indoor heat dissipation terminal and the four-way valve; The first expansion valve is disposed between the outdoor heat exchanger and the indoor heat dissipation terminal, and is used to increase the flow resistance of the refrigerant passing through the first expansion valve when the opening degree of the first expansion valve is reduced, and to reduce the flow resistance of the refrigerant passing through the first expansion valve when the opening degree of the first expansion valve is increased; A valve box, wherein a first end of the valve box is connected to the gas pipe, a second end of the valve box is connected to the liquid pipe, and a third end of the valve box is connected to the indoor heat dissipation terminal. The valve box is used to switch the heat dissipation mode of the indoor heat dissipation terminal, and the heat dissipation mode includes one of a fan coil heat dissipation mode and a direct expansion heat dissipation terminal heat dissipation mode; An indoor fan drives the indoor air to pass through the fan coil unit by rotating so that the refrigerant and the indoor air can exchange heat; An indoor motor, used for driving the indoor fan; Indoor temperature sensor, used to detect the temperature of the indoor environment; A controller, wherein the controller is configured to: when receiving a control instruction to start the heat dissipation mode of the direct expansion heat dissipation terminal, and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, control the indoor heat dissipation terminal to enter the fan coil heat dissipation mode through the valve box to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment being not greater than the first preset temperature reaches a first preset time, control the indoor heat dissipation terminal to enter the heat dissipation mode of the direct expansion heat dissipation terminal through the valve box to dissipate heat through the direct expansion heat dissipation terminal; When a control instruction to start the direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal.

2. The air conditioning system according to claim 1, characterized in that: The valve box includes: at least one first solenoid valve and at least one second expansion valve, at least one second solenoid valve and at least one third expansion valve; Wherein, the first solenoid valve is connected between the gas pipe and the fan coil unit, and the second expansion valve is connected between the liquid pipe and the fan coil unit; when the first solenoid valve and the second expansion valve are both in an open state, the refrigerant flowing through the fan coil unit performs heat exchange with the indoor air, so that the indoor heat dissipation terminal enters the fan coil unit heat dissipation mode; The second solenoid valve is connected between the gas pipe and the direct expansion heat dissipation terminal, and the third expansion valve is connected between the liquid pipe and the direct expansion heat dissipation terminal; when the second solenoid valve and the third expansion valve are both in an open state, the refrigerant flowing through the direct expansion heat dissipation terminal exchanges heat with the indoor air, so that the indoor heat dissipation terminal enters the direct expansion heat dissipation terminal heat dissipation mode.

3. The air conditioning system according to claim 2, characterized in that: After controlling the indoor heat dissipation terminal to enter the direct expansion heat dissipation terminal heat dissipation mode through the valve box, the controller is further configured to: Determining whether the compressor is in a preset operating state, and when it is determined that the compressor is in the preset operating state, controlling the operating frequency of the compressor, the speed of the indoor motor, and at least one of the first solenoid valves according to the current operating frequency of the compressor and the current temperature of the indoor environment; When it is determined that the compressor does not appear in the preset operating state, the operating frequency of the compressor is controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment.

4. The air conditioning system according to claim 3, characterized in that: When it is determined that the compressor is in the preset operating state, the operating frequency of the compressor, the speed of the indoor motor and at least one of the first solenoid valves are controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment, the controller is specifically configured as follows: When the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than a second preset temperature, the operating frequency of the compressor is controlled to be maintained at the current operating frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed; When the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, the operating frequency of the compressor is controlled to be reduced by a first preset frequency, the speed of the indoor motor is controlled to be zero, and all the first solenoid valves are controlled to be closed; When the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor has not reached the maximum operating frequency, at least one of the first solenoid valves is controlled to be opened, and the speed of the indoor motor is controlled to be the lowest speed, and after a second preset time, all of the first solenoid valves are controlled to be closed, and the speed of the indoor motor is controlled to be zero, and then, according to the number of the first solenoid valves controlled to be opened, it is determined whether to return to the step of determining whether the compressor is in the preset working state; When the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to remain at the maximum operating frequency, the speed of the indoor motor is controlled to be zero, and all of the first solenoid valves are controlled to be closed.

5. The air conditioning system according to claim 4, characterized in that: When it is determined that the compressor does not have the preset operating condition, when the operating frequency of the compressor is controlled according to the current operating frequency of the compressor and the current temperature of the indoor environment, the controller is specifically configured as follows: When the absolute value of the difference between the current temperature of the indoor environment and the set temperature is less than the second preset temperature, controlling the operating frequency of the compressor to maintain at the current operating frequency; When the difference between the current temperature of the indoor environment and the set temperature is greater than the second preset temperature, controlling the operating frequency of the compressor to decrease by a second preset frequency; When the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature, and the current operating frequency of the compressor has not reached the maximum operating frequency, the operating frequency of the compressor is controlled to increase by a third preset frequency, and the step of determining whether the compressor is in the preset operating state is returned to be executed; When the difference between the set temperature and the current temperature of the indoor environment is greater than the second preset temperature and the current operating frequency of the compressor reaches the maximum operating frequency, the operating frequency of the compressor is controlled to be maintained at the maximum operating frequency.

6. The air conditioning system according to claim 4, characterized in that: Determining whether to return to the step of determining whether the compressor is in the preset operating state according to the number of times the first solenoid valve is controlled to be opened, the controller is specifically configured as follows: When the opening number of the first solenoid valve is controlled to reach the maximum number, the step of determining whether the compressor is in the preset working state is not returned to be executed; When the opening number of the first solenoid valve is controlled to not reach the maximum number, the process returns to the step of determining whether the compressor is in the preset operating state.

7. The air conditioning system according to claim 3, characterized in that: When the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration for which the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature reaches a first preset time, before the indoor heat dissipation terminal is controlled by the valve box to enter the direct expansion heat dissipation terminal heat dissipation mode, the controller is further configured to: The compressor is controlled to operate at a frequency lower than the current operating frequency.

8. The air conditioning system according to claim 3, characterized in that: The air conditioning system further includes a pressure sensor, which is disposed between the four-way valve and the valve box. The pressure sensor is used to detect the refrigerant pressure in the air pipe. When determining whether the compressor is in a preset working state, the controller is specifically configured as follows: When the pressure value detected by the pressure sensor is greater than a preset pressure value, it is determined that the compressor is in a preset working state; When the pressure value detected by the pressure sensor is not greater than the preset pressure value, it is determined that the compressor is not in the preset operating state.

9. The air conditioning system according to claim 1, characterized in that: The direct expansion heat dissipation terminal includes a direct expansion radiator and / or a direct expansion floor heating coil.

10. A method for controlling an air conditioning system, characterized in that: For use in an air conditioning system according to any one of claims 1 to 9, the method comprises the following steps: When a control instruction for starting a heat dissipation mode of a direct expansion heat dissipation terminal is received, and the difference between the set temperature and the current temperature of the indoor environment is greater than a first preset temperature, the indoor heat dissipation terminal is controlled by the valve box to enter a fan coil heat dissipation mode to reduce the temperature difference between the set temperature and the current temperature of the indoor environment, until the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, and the duration of the difference between the set temperature and the current temperature of the indoor environment being not greater than the first preset temperature reaches a first preset time, the indoor heat dissipation terminal is controlled by the valve box to enter the heat dissipation mode of the direct expansion heat dissipation terminal to dissipate heat through the direct expansion heat dissipation terminal; When a control instruction to start the direct expansion cooling terminal cooling mode is received, and the difference between the set temperature and the current temperature of the indoor environment is not greater than the first preset temperature, the indoor cooling terminal is controlled by the valve box to enter the direct expansion cooling terminal cooling mode to dissipate heat through the direct expansion cooling terminal.

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