Air conditioner

Abstract

The invention relates to an air conditioner which comprises a refrigerant loop in which a refrigerant circulates through a compressor, an indoor heat exchanger, a first expansion valve, a flash evaporator, a second expansion valve and an outdoor heat exchanger in sequence; an indoor heat exchanger; an outdoor temperature sensor; a water inlet temperature sensor; an exhaust temperature sensor; an outlet water temperature sensor; the controller is configured to perform first logical operation based on the current outdoor temperature and the water inlet temperature to obtain a target suction superheat degree when the outdoor temperature is lower than a first preset temperature; the action opening degree of the second expansion valve is adjusted to reach the target air suction superheat degree; performing second logic operation based on the frequency of the current compressor to obtain a target exhaust superheat degree; when the exhaust superheat degree and the target exhaust superheat degree meet the first condition, after a first preset time period, the target suction superheat degree is increased; and when the exhaust superheat degree and the target exhaust superheat degree meet the second condition, after the first preset time period, the target suction superheat degree is reduced to guarantee the heating effect.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioners, and in particular to an air conditioner. Background Art

[0002] The air conditioner usually includes a refrigerant circuit, in which the refrigerant flows through the compressor, condenser, expansion valve, and evaporator in sequence to circulate. An outdoor temperature sensor is provided at the outdoor unit of the air conditioner to detect the outdoor temperature, and a water inlet temperature sensor is provided at the water inlet to detect the water inlet temperature.

[0003] In areas with low outdoor temperatures, a flash evaporator is also installed in the refrigerant circuit to ensure indoor heating needs. The flash evaporator is used to replenish air to the compressor, thereby improving the efficiency of the compressor. The flash evaporator is set to prevent liquid from entering the suction side of the compressor, so it is very important to control the suction superheat of the air conditioner.

[0004] In the related art, the target suction superheat is not adjusted according to the outdoor temperature. The target suction superheat uses a fixed value and controls the flow of refrigerant through the expansion valve to meet the target suction superheat temperature. The suction superheat controlled in this case is inaccurate, and the refrigerant state control on the suction side of the compressor is not precise. In areas with low outdoor temperatures, the detection results of the suction superheat will also be affected. The related art cannot correct the suction superheat to meet the demand for indoor heating.

[0005] In view of this, this application is filed. Summary of the invention

[0006] The present invention solves one of the technical problems in the related art at least to a certain extent.

[0007] To this end, the present application aims to provide an air conditioner to facilitate precise heating control of the air conditioner and improve the heating effect.

[0008] To achieve the above object, the present invention provides an air conditioner, comprising:

[0009] A compressor comprising a first air supply port, an air intake port and an air discharge port;

[0010] The flash evaporator comprises a first refrigerant port, a second refrigerant port and a second air supply port, wherein the first air supply port is connected to the second air supply port;

[0011] A refrigerant circuit, in which the refrigerant is discharged through the exhaust port of the compressor, passes through the indoor heat exchanger and the first expansion valve in sequence, and then flows into the flash evaporator through the first refrigerant port; the refrigerant in the flash evaporator flows out through the second refrigerant port, passes through the second expansion valve and the outdoor heat exchanger, and then flows into the compressor through the air intake port; the refrigerant in the flash evaporator flows out through the second air supply port, passes through the first air supply port, and then flows into the compressor for circulation;

[0012] The indoor heat exchanger includes a water inlet and a water outlet. The heat exchange medium enters through the water inlet to exchange heat with the refrigerant circuit and then flows out through the water outlet.

[0013] An outdoor temperature sensor is provided in the outdoor unit of the air conditioner and is used to detect the outdoor temperature;

[0014] An inlet water temperature sensor is provided at the water inlet and is used to detect the inlet water temperature;

[0015] An exhaust temperature sensor is disposed at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor;

[0016] An outlet water temperature sensor is provided at the outlet of the water and is used to detect the outlet water temperature;

[0017] The controller is configured to: when the indoor heat exchanger works as a condenser, define the difference between the exhaust temperature and the outlet water temperature as the exhaust superheat;

[0018] When the outdoor temperature is lower than the first preset temperature, a first logic operation is performed based on the current outdoor temperature and the inlet water temperature to obtain a target suction superheat; and the action opening of the second expansion valve is adjusted to achieve the target suction superheat;

[0019] Performing a second logic operation based on the current frequency of the compressor to obtain a target exhaust gas superheat;

[0020] When the exhaust gas superheat and the target exhaust gas superheat meet a first condition, after a first preset time period, the target intake air superheat is increased;

[0021] When the exhaust gas superheat and the target exhaust gas superheat satisfy a second condition, the target intake air superheat is reduced after a first preset period of time.

[0022] In some embodiments of the present application, the controller is configured to:

[0023] When the outdoor temperature is lower than the second preset temperature and not lower than the first preset temperature, a first logical operation is performed based on the current outdoor temperature and the inlet water temperature to obtain a target intake superheat; and the action opening of the second expansion valve is adjusted to achieve the target intake superheat.

[0024] In some embodiments of the present application, the controller is configured as follows: when the outdoor temperature is not lower than a second preset temperature, the target intake superheat is set to a superheat preset value, and the action opening of the second expansion valve is adjusted to reach the superheat preset value.

[0025] In some embodiments of the present application, the controller is configured as follows: a value range of the target intake superheat is preset in the controller, and when the target intake superheat increases to a maximum value of its value range, the target intake superheat is controlled not to increase any more.

[0026] In some embodiments of the present application, the controller is configured to: when the target suction air superheat is reduced to the minimum value of its value range, control the target suction air superheat to not be reduced any more.

[0027] In some embodiments of the present application, the controller is configured to: use an outdoor temperature sensor to periodically detect the outdoor temperature, and obtain a target suction air superheat within a corresponding period based on the detected outdoor temperature.

[0028] In some embodiments of the present application, it also includes:

[0029] A suction temperature sensor is arranged at the suction port of the compressor and is used to detect the suction temperature of the compressor;

[0030] An outdoor coil temperature sensor is arranged on the outdoor heat exchanger and is used to detect the coil temperature of the outdoor heat exchanger;

[0031] The difference between the suction temperature and the coil temperature is defined as the suction superheat;

[0032] Define the difference between the suction superheat in the current cycle and the target suction superheat as the suction superheat adjustment value;

[0033] The proportional component is obtained by calculation based on the suction superheat adjustment value;

[0034] Define the difference between the suction superheat adjustment value in the current cycle and the suction superheat adjustment value in the previous cycle as the suction superheat change difference;

[0035] The proportional component is obtained by calculation based on the difference of suction superheat change;

[0036] A third logic operation is performed based on the proportional component and the differential component to obtain the action opening degree of the second expansion valve.

[0037] In some embodiments of the present application, the controller is configured to obtain a target opening of the second expansion valve based on the sum of the current opening of the second expansion valve and the action opening of the second expansion valve.

[0038] In some embodiments of the present application, the indoor heat exchange is a plate heat exchanger, and the heat exchange medium is water.

[0039] Another aspect of the present invention provides an air conditioner, comprising:

[0040] A compressor comprising a first air supply port, an air intake port and an air discharge port;

[0041] The flash evaporator comprises a first refrigerant port, a second refrigerant port and a second air supply port, wherein the first air supply port is connected to the second air supply port;

[0042] A refrigerant circuit, in which the refrigerant is discharged through the exhaust port of the compressor, passes through the indoor heat exchanger and the first expansion valve in sequence, and then flows into the flash evaporator through the first refrigerant port; the refrigerant in the flash evaporator flows out through the second refrigerant port, passes through the second expansion valve and the outdoor heat exchanger, and then flows into the compressor through the air intake port; the refrigerant in the flash evaporator flows out through the second air supply port, passes through the first air supply port, and then flows into the compressor for circulation;

[0043] The indoor heat exchanger includes a water inlet and a water outlet. The heat exchange medium enters through the water inlet to exchange heat with the refrigerant circuit and then flows out through the water outlet.

[0044] An outdoor temperature sensor is provided in the outdoor unit of the air conditioner and is used to detect the outdoor temperature;

[0045] An inlet water temperature sensor is provided at the water inlet and is used to detect the inlet water temperature;

[0046] An exhaust temperature sensor is disposed at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor;

[0047] An outlet water temperature sensor is provided at the outlet of the water and is used to detect the outlet water temperature;

[0048] The controller is configured to: when the indoor heat exchanger works as a condenser, define the difference between the exhaust temperature and the outlet water temperature as the exhaust superheat;

[0049] When the outdoor temperature is lower than the first preset temperature, a first logic operation is performed based on the current outdoor temperature and the inlet water temperature to obtain a target suction superheat; and the action opening of the second expansion valve is adjusted to achieve the target suction superheat;

[0050] Performing a second logic operation based on the current frequency of the compressor to obtain a target exhaust gas superheat;

[0051] When the difference between the exhaust gas superheat and the target exhaust gas superheat satisfies a third condition, after a first preset time period, the target intake superheat is increased;

[0052] When the difference between the exhaust gas superheat and the target exhaust gas superheat satisfies a fourth condition, the target intake air superheat is reduced after a first preset period of time.

[0053] 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

[0054] Figure 1 is a schematic diagram of the system structure of an air conditioner according to one embodiment of the present application;

[0055] Figure 2is a schematic diagram of a refrigerant circulation in a heating mode of an air conditioner according to one embodiment of the present application;

[0056] Figure 3 is a schematic diagram of a refrigerant circulation in a cooling mode of an air conditioner according to one embodiment of the present application;

[0057] Figure 4 This is a first control process for regulating the suction superheat of an air conditioner according to one embodiment of the present application;

[0058] Figure 5 This is a second control process for regulating the suction superheat of an air conditioner according to one embodiment of the present application;

[0059] Figure 6 This is a third control process for adjusting the suction superheat of an air conditioner according to one embodiment of the present application;

[0060] Figure 7 This is a general flow chart of regulating and controlling the suction superheat of an air conditioner according to one embodiment of the present application;

[0061] Figure 8 This is a control process for adjusting the suction superheat of an air conditioner according to another embodiment of the present application;

[0062] Fig. 9 This is a general flow chart of regulating and controlling the suction superheat of an air conditioner according to another embodiment of the present application;

[0063] Fig.10 is a flow chart of the operation opening control of the second expansion valve of the air conditioner according to one embodiment of the present application;

[0064] Fig.11 It is a hardware configuration block diagram according to one implementation mode of the present application.

[0065] In the above figures: compressor 1; first air supply port 11; air intake port 12; exhaust port 13; exhaust temperature sensor 2; four-way valve 3; indoor heat exchanger 4; water inlet 41; water outlet 42; first expansion valve 5; flash evaporator 6; first refrigerant port 61; second refrigerant port 62; second air supply port 63; second expansion valve 7; controller 71; bus 81; memory 82; processor 83; communication interface 84; outdoor heat exchanger 9; outdoor coil temperature sensor 10. DETAILED DESCRIPTION

[0066] The present invention is described in detail below by way of exemplary embodiments. However, it should be understood that elements, structures, and features in one embodiment may also be beneficially combined in other embodiments without further description.

[0067] In the following, reference will be made to the Figure 1-Figure 11 The embodiments of the present application are described in detail.

[0068] In the present application, the air conditioner includes an air conditioner indoor unit and an air conditioner outdoor unit. When the air conditioner operates in a cooling mode, the air conditioner performs a refrigeration cycle of the air conditioner indoor unit by using a compressor 1, an outdoor heat exchanger 9, a first expansion valve 5, a flash evaporator 6, a second expansion valve 7 and an indoor heat exchanger 4.

[0069] The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation, and supplies refrigerant to the heat exchange medium that has been conditioned and heat exchanged, provides cold capacity to the heat exchange medium through the heat absorption process of the refrigerant, and realizes the temperature regulation of the indoor heat exchange medium.

[0070] The compressor 1 compresses the low-temperature and low-pressure refrigerant gas to discharge the high-temperature and high-pressure refrigerant gas, and the discharged refrigerant gas flows into the outdoor heat exchanger 9. The outdoor heat exchanger 9 condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0071] The first expansion valve 5 or the second expansion valve 7 expands the high-temperature and high-pressure liquid-phase refrigerant condensed in the outdoor heat exchanger 9 into a low-pressure liquid-phase refrigerant.

[0072] The flash evaporator 6 is used to separate the low-pressure liquid refrigerant into the gaseous refrigerant to replenish the compressor 1.

[0073] The indoor heat exchanger 4 evaporates the expanded refrigerant and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor 1. The indoor heat exchanger 4 can achieve a cooling effect by exchanging heat with the indoor heat exchange medium using the latent heat of evaporation of the refrigerant.

[0074] During the entire refrigeration cycle, the air conditioner indoor unit can regulate the temperature of the indoor heat exchange medium.

[0075] When the air conditioner operates in a heating mode, the air conditioner performs a heating cycle of the indoor unit of the air conditioner through the compressor 1 , the outdoor heat exchanger 9 , the expansion valve and the indoor heat exchanger 4 .

[0076] The heating cycle includes a series of processes involving compression, condensation, expansion and evaporation, and supplies refrigerant to the heat exchange medium that has been conditioned and heat exchanged, and provides heat to the heat exchange medium through the heat release process of the refrigerant to achieve temperature regulation of the indoor heat exchange medium.

[0077] When the heating cycle is running, the compressor 1 compresses the refrigerant gas in a low-temperature and low-pressure state and discharges the refrigerant gas in a high-temperature and high-pressure state, and the discharged refrigerant gas flows into the indoor heat exchanger 4. The indoor heat exchanger 4 condenses the compressed refrigerant into a liquid phase, and the heat generated by the condensation is heat-exchanged with the indoor air flowing through the indoor heat exchanger 4, thereby increasing the temperature of the heat exchange medium.

[0078] The first expansion valve 5 or the second expansion valve 7 expands the high-temperature and high-pressure liquid-phase refrigerant condensed in the outdoor heat exchanger 9 into a low-pressure liquid-phase refrigerant.

[0079] The flash evaporator 6 is used to separate the low-pressure liquid refrigerant into the gaseous refrigerant to replenish the compressor 1.

[0080] The outdoor heat exchanger 9 evaporates the expanded refrigerant and returns the refrigerant gas in a low temperature and low pressure state to the compressor 1. The outdoor heat exchanger 9 can achieve temperature regulation of the indoor heat exchange medium by utilizing the condensation heat release of the refrigerant to exchange heat with the heat exchange medium.

[0081] During the entire heating cycle, the air conditioner indoor unit can adjust the temperature of the indoor heat exchange medium.

[0082] The indoor heat exchanger 4 and the outdoor heat exchanger 9 function as a condenser or an evaporator. When the indoor heat exchanger 4 functions as a condenser, the air conditioner indoor unit functions as a heater in a heating mode, and when the indoor heat exchanger 4 functions as an evaporator, the air conditioner indoor unit functions as a cooler in a cooling mode.

[0083] As attached Figure 1-Figure 11 As shown, in one embodiment of the air conditioner of the present invention.

[0084] The air conditioner includes a compressor 1, a flash evaporator 6, an indoor heat exchanger 4, an outdoor heat exchanger 9, a first expansion valve 5, a second expansion valve 7, a four-way valve 3 and a refrigerant circuit.

[0085] The indoor heat exchanger 4 and the outdoor heat exchanger 9 are both connected to the compressor 1 through the four-way valve 3. The first expansion valve 5 and the second expansion valve 7 are electronic expansion valves. In the heating mode, the second expansion valve 7 can expand the liquid refrigerant that has undergone the condensation process into a low-pressure liquid refrigerant. In the cooling mode, the first expansion valve 5 can expand the liquid refrigerant that has undergone the condensation process into a low-pressure liquid refrigerant.

[0086] The compressor 1 includes a first air supply port 11, an air intake port 12 and an air exhaust port 13. The refrigerant that absorbs heat and undergoes an evaporation process enters the compressor 1 from the air intake port 12. The compressor 1 compresses the gaseous refrigerant into a high-temperature and high-pressure state and then discharges it from the exhaust port 13. The first air supply port 11 is connected to the flash evaporator 6, and the compressor 1 is supplied with air through the flash evaporator 6 to reduce the enthalpy value, thereby ensuring the heating efficiency of the compressor 1.

[0087] The indoor heat exchanger 4 and the outdoor heat exchanger 9 are respectively connected to the compressor 1 through the four-way valve 3 in the refrigerant circuit. The four-way valve 3 includes a first valve port, a second valve port, a third valve port and a fourth valve port. Among them, the air intake port 12 of the compressor 1 is fixedly connected to the first valve port, the air exhaust port 13 of the compressor 1 is fixedly connected to the third valve port, the second valve port is connected to the indoor heat exchanger 4, and the fourth valve port is connected to the outdoor heat exchanger 9.

[0088] When the air conditioner is in cooling mode, the first valve port is connected to the second valve port, and the third valve port is connected to the fourth valve port. When the air conditioner is in heating mode, the first valve port is connected to the fourth valve port, and the second valve port is connected to the third valve port.

[0089] The flash evaporator 6 includes a first refrigerant port 61 , a second refrigerant port 62 and a second air supply port 63 . The first air supply port 11 of the compressor 1 is connected to the second refrigerant port 62 of the flash evaporator 6 .

[0090] In the refrigerant circuit of the heating cycle, the refrigerant is discharged through the exhaust port 13 of the compressor 1, passes through the indoor heat exchanger 4 and the first expansion valve 5 in sequence, and then flows into the flash evaporator 6 through the first refrigerant port 61. The refrigerant in the flash evaporator 6 flows out through the second refrigerant port 62, passes through the second expansion valve 7 and the outdoor heat exchanger 9, and then flows into the compressor 1 through the air intake port 12; the refrigerant in the flash evaporator 6 flows out through the second air supply port 63, and then flows into the compressor 1 through the first air supply port 11 for circulation. In the heating cycle, the indoor heat exchanger 4 is used as a condenser, and the outdoor heat exchanger 9 is used as an evaporator.

[0091] The indoor heat exchanger 4 can be set as a plate heat exchanger, and the indoor heat exchanger 4 includes a water inlet 41 and a water outlet 42. The heat exchange medium enters through the water inlet 41 to exchange heat with the refrigerant circuit, and the heat exchange medium flows out through the water outlet 42 after heat exchange. The heat exchange medium can be set as water, and the water temperature increases after heat exchange with the refrigerant, which can provide users with domestic hot water.

[0092] In addition, the air conditioner is provided with a controller 71 to control the operation of various components in the air conditioner so that the various components of the air conditioner can operate to realize various predetermined functions of the air conditioner. The controller 71 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 a power-on or power-off instruction received from a user, the controller 71 can perform an operation related to the object selected by the power-on or power-off instruction.

[0093] The air conditioner is also provided with a control device, which is exemplarily a remote controller, which has the function of communicating with the controller 71 using infrared or other communication methods. The remote controller is used for the user to perform various controls on the air conditioner and realize the interaction between the user and the air conditioner.

[0094] The embodiment of the present application also provides a hardware structure diagram of a controller 71, the controller 71 includes a processor 83, and optionally, also 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.

[0095] 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).

[0096] 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) read-only compact disc (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.), 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 instructions or data structures and can be accessed by a computer, and the embodiment of the present 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 computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, so as to realize the control method of the air conditioner provided in the embodiment of the present application.

[0097] 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.

[0098] The bus 81 may be a peripheral component interconnect (PCI) bus 81 or an extended industry standard architecture (EISA) bus 81. The bus 81 may be divided into an address bus 81, a data bus 81, a control bus 81, etc. Fig.11 Only one thick line is used in the figure, but it does not mean that there is only one bus 81 or only one type of bus 81.

[0099] In some embodiments, the air conditioner further includes an outdoor temperature sensor, a water inlet temperature sensor, an exhaust temperature sensor 2 , a water outlet temperature sensor, an air intake temperature sensor and an outdoor coil temperature sensor 10 .

[0100] The outdoor temperature sensor is disposed in the outdoor unit of the air conditioner and is used to detect the outdoor temperature. The outdoor temperature sensor is electrically connected to the controller 71 , and detects the outdoor temperature and sends the outdoor temperature to the controller 71 in the form of an electrical signal.

[0101] The water inlet temperature sensor is disposed at the water inlet 41 of the indoor heat exchanger 4 and is used to detect the water inlet temperature. The water inlet temperature sensor is electrically connected to the controller 71, detects the water inlet temperature of the heat exchange medium, and sends the water inlet temperature to the controller 71 in the form of an electrical signal.

[0102] The exhaust temperature sensor 2 is disposed at the exhaust port 13 of the compressor 1, and is used to detect the exhaust temperature of the compressor 1. The exhaust temperature sensor 2 is electrically connected to the controller 71, and the exhaust temperature sensor 2 detects the exhaust temperature of the heat exchange medium and sends the exhaust temperature to the controller 71 in the form of an electrical signal.

[0103] The outlet water temperature sensor is disposed at the outlet 42 of the indoor heat exchanger 4, and is used to detect the outlet water temperature. The outlet water temperature sensor is electrically connected to the controller 71, and detects the outlet water temperature of the heat exchange medium, and sends the outlet water temperature to the controller 71 in the form of an electrical signal.

[0104] The intake air temperature sensor is disposed at the intake port 12 of the compressor 1, and is used to detect the intake air temperature of the compressor 1. The intake air temperature sensor is electrically connected to the controller 71, and detects the intake air temperature of the compressor 1, and sends the intake air temperature to the controller 71 in the form of an electrical signal.

[0105] The outdoor coil temperature sensor 10 is disposed at the middle coil of the outdoor heat exchanger 9, and is used to detect the coil temperature of the outdoor heat exchanger 9. The outdoor coil temperature sensor 10 is electrically connected to the controller 71, and the outdoor coil temperature sensor 10 detects the coil temperature of the outdoor heat exchanger 9 and sends the coil temperature of the outdoor heat exchanger 9 to the controller 71 in the form of an electrical signal.

[0106] The controller 71 is configured to define the difference between the exhaust gas temperature and the outlet water temperature as the exhaust gas superheat when the indoor heat exchanger 4 works as a condenser.

[0107] When the outdoor temperature is lower than the first preset temperature, a first logical operation is performed based on the current outdoor temperature and the inlet water temperature to obtain a target intake superheat, and the controller 71 is used to control the opening of the second expansion valve 7 to achieve the target intake superheat.

[0108] A second logical operation is performed based on the current frequency of the compressor 1 to obtain a target exhaust gas superheat.

[0109] When the exhaust superheat and the target exhaust superheat meet the first condition, the target intake superheat is increased after a first preset period of time. When the exhaust superheat and the target exhaust superheat meet the second condition, the target intake superheat is decreased after a first preset period of time.

[0110] In the present application, when the outdoor temperature sensor detects that the outdoor temperature is lower than the first preset temperature, it means that the outdoor temperature is low at this time. When the outdoor temperature is low, the deviation of the outdoor coil temperature detected by the outdoor coil temperature sensor 10 will be large, thereby affecting the detection accuracy of the suction superheat. Therefore, at this time, controlling the action opening of the second expansion valve 7 only by detecting the suction superheat will cause a large deviation in the actual result of the suction superheat.

[0111] When the outdoor temperature is high, in the heating mode, the indoor temperature is high. This application uses the exhaust superheat and the exhaust superheat with more accurate detection data to correct the target suction superheat value when the outdoor temperature is low, so as to make the suction superheat control more accurate. It can be set that the first preset temperature can be set to -15°C.

[0112] In some embodiments, when the outdoor temperature is lower than the second preset temperature and not lower than the first preset temperature, a first logic operation is performed based on the current outdoor temperature and the inlet water temperature to obtain a target suction superheat. The action opening of the second expansion valve 7 is adjusted to achieve the target suction superheat. The second preset temperature can be set to 3°C, and the first preset temperature can be set to -15°C.

[0113] At this time, through the first logical operation, the action opening of the second electronic expansion valve is continuously adjusted, so that the current exhaust superheat is continuously close to the target exhaust superheat, thereby improving the control accuracy of the suction superheat, ensuring that there is no liquid on the suction side of the compressor 1, and improving the protection for the low-temperature heating operation of the compressor 1.

[0114] In some embodiments, when the outdoor temperature is not lower than the second preset temperature, the target suction superheat is set to the preset superheat value, and the action opening of the second expansion valve 7 is adjusted to reach the preset superheat value. It can be set that the second preset temperature can be set to 3°C, the preset superheat value is a fixed value, and the preset superheat value can be set to 0.

[0115] In some embodiments, the first logical operation is: target suction superheat = (Toutdoor + K1) * K2 + (K3-Twaterin) * K4 + K5. Wherein, Toutdoor is the outdoor temperature, Twaterin is the inlet water temperature, K1, K2, K3, K4 and K5 are constants. It can be set that K1 = 12; K2 = 0.05; K3 = 36; K4 = 0.08; K5 = 1.

[0116] When calculating the target intake superheat, the present application only uses the detected outdoor temperature and water inlet temperature to calculate the target intake superheat. Fewer parameter values ​​are required for the calculation, which is easier to measure. The accumulated deviations of multiple parameter values ​​for calculation can be reduced, and the calculation accuracy of the target intake superheat can be improved. The target intake superheat obtained by controlling and adjusting the second expansion valve 7 by the controller 71 is more accurate, thereby improving the heating efficiency of the air conditioner during low-temperature heating.

[0117] In some embodiments, the second logical operation is: target exhaust superheat=A*compressor 1 frequency+B, wherein A and B are constants, which can be set as A=0.24 and B=20.

[0118] The first condition is: exhaust superheat ≤ target exhaust superheat - E, where E is a constant and can be set to E=5.

[0119] That is, when the exhaust superheat is less than or equal to the target exhaust superheat - E, it means that the exhaust superheat is low and the target exhaust superheat is high. When the exhaust superheat is adjusted to the target exhaust superheat, the target intake superheat is corrected. After the first preset time period, the target intake superheat is increased.

[0120] It can be set that after every first preset time period, the target suction superheat degree=current target suction superheat degree+F, wherein F is a constant and F can be set to 1. The first preset time period can be set to 5 minutes.

[0121] In some embodiments, the controller 71 is preset with a target suction superheat value range, and when the target suction superheat increases to a maximum value of the value range, the target suction superheat is controlled not to increase any further. The maximum value of the target suction superheat value range can be set to 0.

[0122] In some embodiments, when the difference between the exhaust gas superheat and the target exhaust gas superheat satisfies a third condition, the target intake air superheat is increased after a first preset period of time.

[0123] The third condition is: exhaust superheat - target exhaust superheat ≤ -E, where E is a constant and can be set to E=5.

[0124] That is, when exhaust superheat - target exhaust superheat ≤ -E, it means that the exhaust superheat is low and the target exhaust superheat is high. When adjusting the exhaust superheat to the target exhaust superheat, the target intake superheat is corrected. After the first preset time period, the target intake superheat is increased.

[0125] It can be set that after every first preset time period, the target suction superheat degree=current target suction superheat degree+F, wherein F is a constant and F can be set to 1. The first preset time period can be set to 5 minutes.

[0126] In some embodiments, the controller 71 is preset with a target suction superheat value range, and when the target suction superheat increases to a maximum value of the value range, the target suction superheat is controlled not to increase any further. The maximum value of the target suction superheat value range can be set to 0.

[0127] In some embodiments, the second condition is: exhaust superheat ≥ target exhaust superheat + C, where C is a constant, which can be set to C=4.

[0128] That is, when the exhaust superheat ≥ the target exhaust superheat + C, it means that the exhaust superheat is high and the target exhaust superheat is low. While adjusting the exhaust superheat to the target exhaust superheat, the target intake superheat is corrected. After the first preset time period, the target intake superheat is lowered.

[0129] It can be set that after every first preset time period, the target suction superheat degree=current target suction superheat degree-D, wherein D is a constant and D can be set to 1. The first preset time period can be set to 5 minutes.

[0130] In some embodiments, the controller 71 is preset with a value range of the target suction superheat, and when the target suction superheat decreases to the minimum value of its value range, the target suction superheat is controlled not to decrease any more. The minimum value of the value range of the target suction superheat can be set to -2.

[0131] In some embodiments, when the difference between the exhaust superheat and the target exhaust superheat satisfies a fourth condition, the target intake superheat is reduced after a first preset time period.

[0132] The fourth condition is: exhaust superheat - target exhaust superheat ≥ C, where C is a constant and can be set to C=4.

[0133] That is, when exhaust superheat - target exhaust superheat ≥ C, it means that the exhaust superheat is high and the target exhaust superheat is low. When adjusting the exhaust superheat to the target exhaust superheat, the target intake superheat is corrected. After the first preset time period, the target intake superheat is reduced.

[0134] It can be set that after every first preset time period, the target suction superheat degree=current target suction superheat degree-D, wherein D is a constant and D can be set to 1. The first preset time period can be set to 5 minutes.

[0135] In some embodiments, the controller 71 is preset with a value range of the target suction superheat, and when the target suction superheat decreases to the minimum value of its value range, the target suction superheat is controlled not to decrease any more. The minimum value of the value range of the target suction superheat can be set to -2.

[0136] In some embodiments, the outdoor temperature sensor periodically detects the outdoor temperature, and the target suction superheat in the corresponding period is obtained based on the detected outdoor temperature. The action opening of the second expansion valve 7 is controlled by the obtained target suction superheat, so that the current suction superheat is periodically adjusted to the target suction superheat, thereby achieving precise control of the target suction superheat, improving the heating performance of the compressor 1, and preventing the suction side of the compressor 1 from sucking in liquid refrigerant.

[0137] In some embodiments, the difference between the suction air temperature and the coil temperature is defined as the suction air superheat, and the difference between the suction air superheat in the current cycle and the target suction air superheat is defined as the suction air superheat adjustment value.

[0138] The control method for controlling the action opening of the second expansion valve 7 by the target suction superheat is as follows: a proportional component is obtained by calculation based on the suction superheat adjustment value. The difference between the suction superheat adjustment value in the current cycle and the suction superheat adjustment value in the previous cycle is defined as the suction superheat change difference, a differential component is obtained by calculation based on the suction superheat change difference, and a third logic operation is performed based on the proportional component and the differential component to obtain the required action opening of the second expansion valve 7.

[0139] In the step of calculating and obtaining the proportional component based on the suction superheat adjustment value, the proportional component=the suction superheat adjustment value*P, wherein P is a constant.

[0140] In the step of calculating and obtaining the differential component based on the suction air superheat variation difference, the differential component=suction air superheat variation difference*D, wherein D is a constant.

[0141] In some embodiments, the third logic operation includes: performing an operation through a proportional component, a differential component and a constant Gain to obtain a required action opening degree of the second expansion valve 7 .

[0142] The third logic is: (proportional component+differential component) / constant Gain=required action opening degree of the second expansion valve 7 .

[0143] The target opening degree of the second expansion valve 7 is obtained by summing the current actuation opening degree of the second expansion valve 7 and the required actuation opening degree of the second expansion valve 7 .

[0144] When the required action opening of the second expansion valve 7 is a positive number, the controller 71 controls the second expansion valve 7 to increase its action opening to reach the target opening of the second expansion valve 7, thereby achieving precise control of the suction superheat by controlling the second expansion valve 7.

[0145] When the required action opening of the second expansion valve 7 is a negative number, the controller 71 controls the second expansion valve 7 to reduce its action opening to reach the target opening of the second expansion valve 7, thereby achieving precise control of the suction superheat by controlling the second expansion valve 7.

[0146] In the description of the present invention, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0147] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0148] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

[0149] In the present invention, the terms "first", "second", "third", and "fourth" 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. Therefore, the features defined as "first", "second", "third", and "fourth" may explicitly or implicitly include one or more of the features.

[0150] In the present invention, unless otherwise clearly specified and limited, a first feature being "on" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0151] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0152] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An air conditioner, characterized in that: include: A compressor comprising a first air supply port, an air intake port and an air discharge port; The flash evaporator comprises a first refrigerant port, a second refrigerant port and a second air supply port, wherein the first air supply port and the second air supply port are connected; A refrigerant circuit, in which the refrigerant is discharged through the exhaust port of the compressor, passes through the indoor heat exchanger and the first expansion valve in sequence, and then flows into the flash evaporator through the first refrigerant port; the refrigerant in the flash evaporator flows out through the second refrigerant port on one route, passes through the second expansion valve and the outdoor heat exchanger, and then flows into the compressor through the air intake port; the refrigerant in the flash evaporator flows out through the second air supply port on another route, and flows into the compressor through the first air supply port for circulation; The indoor heat exchanger comprises a water inlet and a water outlet, and the heat exchange medium enters through the water inlet to exchange heat with the refrigerant circuit and then flows out through the water outlet; An outdoor temperature sensor is provided in the outdoor unit of the air conditioner and is used to detect the outdoor temperature; An inlet water temperature sensor is disposed at the water inlet and is used to detect the inlet water temperature; An exhaust temperature sensor, which is arranged at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor; An outlet water temperature sensor is disposed at the outlet and is used to detect the outlet water temperature; The controller is configured to: when the indoor heat exchanger works as a condenser, define the difference between the exhaust temperature and the outlet water temperature as the exhaust superheat; When the outdoor temperature is lower than a first preset temperature, a first logic operation is performed based on the current outdoor temperature and the inlet water temperature to obtain a target suction superheat; adjusting the opening degree of the second expansion valve to achieve the target suction superheat; Performing a second logic operation based on the current frequency of the compressor to obtain a target exhaust gas superheat; When the exhaust gas superheat and the target exhaust gas superheat meet a first condition, after a first preset time period, the target intake air superheat is increased; When the exhaust gas superheat and the target exhaust gas superheat satisfy a second condition, the target intake air superheat is reduced after a first preset time period.

2. The air conditioner according to claim 1, characterized in that: The controller is configured as: When the outdoor temperature is lower than the second preset temperature and not lower than the first preset temperature, a first logical operation is performed based on the current outdoor temperature and the water inlet temperature to obtain a target intake superheat; and the action opening of the second expansion valve is adjusted to achieve the target intake superheat.

3. The air conditioner according to claim 1, characterized in that: The controller is configured to: when the outdoor temperature is not lower than the second preset temperature, set the target suction superheat to a superheat preset value, and adjust the action opening of the second expansion valve to reach the superheat preset value.

4. The air conditioner according to claim 1, characterized in that: The controller is configured as follows: a value range of the target intake air superheat is preset in the controller, and when the target intake air superheat increases to a maximum value of the value range, the target intake air superheat is controlled not to increase any further.

5. The air conditioner according to claim 4, characterized in that: The controller is configured to: when the target intake air superheat is reduced to a minimum value of its value range, control the target intake air superheat to no longer be reduced.

6. The air conditioner according to claim 1, characterized in that: The controller is configured such that: the outdoor temperature sensor periodically detects the outdoor temperature, and obtains a target suction air superheat degree in a corresponding period based on the detected outdoor temperature.

7. The air conditioner according to claim 6, characterized in that: Also includes: An intake temperature sensor is disposed at the intake port of the compressor and is used to detect the intake temperature of the compressor; An outdoor coil temperature sensor is disposed on the outdoor heat exchanger and is used to detect the coil temperature of the outdoor heat exchanger; The difference between the suction temperature and the coil temperature is defined as suction superheat; Define the difference between the suction superheat and the target suction superheat in the current cycle as the suction superheat adjustment value; Obtaining a proportional component by calculation based on the suction superheat adjustment value; Define the difference between the suction superheat adjustment value in the current cycle and the suction superheat adjustment value in the previous cycle as the suction superheat change difference; A differential component is obtained by calculation based on the suction air superheat change difference; A third logic operation is performed based on the proportional component and the differential component to obtain a required action opening degree of the second expansion valve.

8. The air conditioner according to claim 7, characterized in that: The controller is configured to obtain a target opening degree of the second expansion valve based on a sum of a current actuation opening degree of the second expansion valve and a required actuation opening degree of the second expansion valve.

9. The air conditioner according to claim 1, characterized in that: The indoor heat exchange is a plate heat exchanger, and the heat exchange medium is water.

10. An air conditioner, characterized in that: include: A compressor comprising a first air supply port, an air intake port and an air discharge port; The flash evaporator comprises a first refrigerant port, a second refrigerant port and a second air supply port, wherein the first air supply port and the second air supply port are connected; A refrigerant circuit, in which the refrigerant is discharged through the exhaust port of the compressor, passes through the indoor heat exchanger and the first expansion valve in sequence, and then flows into the flash evaporator through the first refrigerant port; the refrigerant in the flash evaporator flows out through the second refrigerant port on one route, passes through the second expansion valve and the outdoor heat exchanger, and then flows into the compressor through the air intake port; the refrigerant in the flash evaporator flows out through the second air supply port on another route, and flows into the compressor through the first air supply port for circulation; The indoor heat exchanger comprises a water inlet and a water outlet, and the heat exchange medium enters through the water inlet to exchange heat with the refrigerant circuit and then flows out through the water outlet; An outdoor temperature sensor is provided in the outdoor unit of the air conditioner and is used to detect the outdoor temperature; An inlet water temperature sensor is disposed at the water inlet and is used to detect the inlet water temperature; An exhaust temperature sensor, which is arranged at the exhaust port of the compressor and is used to detect the exhaust temperature of the compressor; An outlet water temperature sensor is disposed at the outlet and is used to detect the outlet water temperature; The controller is configured to: when the indoor heat exchanger works as a condenser, define the difference between the exhaust temperature and the outlet water temperature as the exhaust superheat; When the outdoor temperature is lower than a first preset temperature, a first logic operation is performed based on the current outdoor temperature and the inlet water temperature to obtain a target suction superheat; adjusting the opening degree of the second expansion valve to achieve the target suction superheat; Performing a second logic operation based on the current frequency of the compressor to obtain a target exhaust gas superheat; When the difference between the exhaust gas superheat and the target exhaust gas superheat satisfies a third condition, after a first preset time period, the target intake air superheat is increased; When the difference between the exhaust gas superheat and the target exhaust gas superheat satisfies a fourth condition, the target intake air superheat is reduced after a first preset time period.

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