Air conditioner

Abstract

The present application provides an air conditioner. The air conditioner includes an indoor unit of the air conditioner, the indoor unit of the air conditioner includes an indoor heat exchanger, the outdoor unit of the air conditioner includes an outdoor heat exchanger and a compressor, the compressor includes a suction port, a discharge port, and a compression chamber communicating with the suction port and the discharge port, so that the refrigerant entering the compression chamber from the suction port is discharged from the discharge port after being compressed by the compressor; it further includes an electronic expansion valve and a four-way valve, which are connected to the indoor heat exchanger, the outdoor heat exchanger, and the compressor, and are used to switch the air conditioner between a refrigeration working condition and a heating working condition; a connecting pipe is connected between the indoor heat exchanger and the outdoor heat exchanger; a controller, the controller is configured to: calculate the difference C1 between the current discharge superheat and the discharge superheat m electronic expansion valve opening adjustment cycles ago, and the difference C2 between the current suction superheat and the suction superheat m electronic expansion valve opening adjustment cycles ago, and the lag coefficient is proportional to (C1 + C2); the electronic expansion valve opening adjustment cycle is proportional to the lag coefficient, so that the air conditioner operates more stably.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and particularly to an air conditioner. Background Art

[0002] With the rapid development of air conditioners, people have put forward higher requirements for the aesthetics of air conditioner installation. In order to strengthen the protection of building culture, many countries in the European Union have formulated draft laws prohibiting the installation of air conditioner outdoor units on the building surface, which has led to the installation of air conditioner outdoor units only on the roof or in designated equipment rooms. The indoor heat exchanger and the outdoor heat exchanger are connected by an on-line pipe, and refrigerant flows in the on-line pipe. The refrigerant flows between the air conditioner indoor unit and the air conditioner outdoor unit through the on-line pipe. Usually, the length of the air conditioner on-line pipe is 5 meters, which cannot meet the connection requirements between a relatively far air conditioner indoor unit and an air conditioner outdoor unit, and only an extended extra-long pipe can be used to connect the air conditioner indoor unit and the air conditioner outdoor unit.

[0003] When using an extra-long on-line pipe, the length of the on-line pipe will increase to about 50 meters. Due to the increase in the length of the on-line pipe, the flow resistance of the refrigerant in the on-line pipe increases, resulting in a decrease in the flow rate of the refrigerant compared to that in the on-line pipe with an original length of 5 meters. The control logic of the original air conditioner is set according to the original length of the on-line pipe and is only applicable to the case of a 5-meter on-line pipe. The original control parameters are no longer applicable to the case of an extra-long pipe. If the original air conditioner control logic is used, it will lead to a lag in the control parameters, and the temperature detection points of the air conditioner system will respond slowly, resulting in an over-adjustment of the opening degree of the electronic expansion valve, so that the air conditioner needs a long time to run stably after startup, and sometimes it will even lead to abnormal operation or shutdown of the air conditioner.

[0004] Currently, the industry has optimized the control parameters for extra-long on-line pipes. Usually, a fixed correction coefficient is preset to correct the control parameters, and the applicable range of the correction coefficient usually covers extra-long on-line pipes with a length of 6 meters to 50 meters.

[0005] Since the preset correction coefficient is a fixed value, under different air conditioner operating states, the correction of the control parameters by the correction coefficient has certain limitations, which will cause the correction coefficient to be unable to effectively correct the control parameters of the air conditioner, resulting in relatively large problems with the control parameters of the air conditioner in the case of an extra-long pipe, and it cannot meet the user's requirement that the correction coefficient for the extra-long pipe can accurately reflect the influence of the extra-long pipe on the control parameters, nor can it meet the user's requirement for the stable operation of the air conditioner with an extra-long pipe. Summary of the Invention

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

[0007] To this end, the present application aims to provide an air conditioner configured to calculate the difference C1 between the current exhaust superheat degree and the exhaust superheat degree before m electronic expansion valve opening adjustment cycles, and the difference C2 between the current suction superheat degree and the suction superheat degree before m electronic expansion valve opening adjustment cycles. There is a direct proportion between the preset hysteresis coefficient and (C1 + C2); the electronic expansion valve opening adjustment cycle is directly proportional to the hysteresis coefficient, so that the opening adjustment cycle of the electronic expansion valve is associated with the hysteresis coefficient, making the air conditioner operate more stably, enabling the air conditioner to adapt to the setting of a longer connecting pipe, and enabling the air conditioner to maintain operation at a higher efficiency.

[0008] The air conditioner according to the present application includes:

[0009] An air conditioner indoor unit, which includes an indoor heat exchanger;

[0010] An air conditioner outdoor unit, which includes an outdoor heat exchanger and a compressor. The compressor includes a suction port, an exhaust port, and a compression chamber communicating with the suction port and the exhaust port, so that the refrigerant entering the compression chamber from the suction port is discharged from the exhaust port after being compressed by the compressor;

[0011] An electronic expansion valve, which is connected between the indoor heat exchanger and the outdoor heat exchanger to throttle the high-temperature and high-pressure refrigerant liquid after the condensation process into a low-pressure refrigerant liquid;

[0012] A four-way valve, which is connected to the indoor heat exchanger, the outdoor heat exchanger, and the compressor, and is used to switch the air conditioner between a refrigeration operating condition and a heating operating condition;

[0013] A pipeline. The indoor heat exchanger, the outdoor heat exchanger, the compressor, the four-way valve, and the electronic expansion valve are connected through the pipeline. The pipeline includes a connecting pipe: the connecting pipe is connected between the indoor heat exchanger and the outdoor heat exchanger;

[0014] A first temperature sensor, which is arranged on the pipeline connected to the exhaust port and is used to detect the exhaust temperature of the compressor;

[0015] A second temperature sensor, which is arranged on the pipeline connected to the suction port and is used to detect the suction temperature of the compressor;

[0016] A controller, which is configured to: when the compressor is running, obtain the exhaust temperature and the suction temperature and calculate the suction superheat degree and the exhaust superheat degree;

[0017] Taking the flow time of one cycle of the refrigerant flowing between the suction port and the exhaust port as an electronic expansion valve opening adjustment cycle, calculate the suction superheat degree value and the exhaust superheat degree value before m electronic expansion valve opening adjustment cycles;

[0018] Calculate the difference C1 between the current exhaust superheat degree and the exhaust superheat degree before the opening adjustment cycle of the m electronic expansion valves, and the difference C2 between the current suction superheat degree and the suction superheat degree before the opening adjustment cycle of the m electronic expansion valves. The lag coefficient is directly proportional to (C1 + C2).

[0019] Regulate the opening adjustment cycle of the electronic expansion valve according to the lag coefficient and in accordance with the direct proportional relationship, so that the opening adjustment cycle of the electronic expansion valve is associated with the flow time of a cycle of the refrigerant flowing between the suction port and the exhaust port during the actual operation of the air conditioner.

[0020] In some embodiments of the present application, the controller is configured to: preset a target exhaust superheat degree that is inversely proportional to the lag coefficient, regulate the single valve adjustment amount of the electronic expansion valve according to the target exhaust superheat degree, and the target exhaust superheat degree is directly proportional to the single valve adjustment amount; when the lag coefficient increases, the target exhaust superheat degree decreases compared to the original exhaust superheat degree, thereby reducing the single valve adjustment amount.

[0021] In some embodiments of the present application, the controller is configured to: preset an outdoor ambient temperature correction coefficient U. The lag coefficient is directly proportional to the outdoor ambient temperature correction coefficient U. The outdoor ambient temperature correction coefficient U is directly proportional to the outdoor ambient temperature constant K. The outdoor ambient temperature correction coefficient U is outdef inversely proportional to the current outdoor temperature T

[0022] In some embodiments of the present application, the controller is configured to: preset a first lag value;

[0023] When the air conditioner is started for the first time, the controller calculates the lag coefficient and compares the magnitude relationship between the lag coefficient and the first lag value,

[0024] If the lag coefficient is not less than the first lag value, recalculate the opening adjustment cycle of the electronic expansion valve and the target exhaust superheat degree according to the lag coefficient, so that the opening adjustment cycle of the electronic expansion valve and the single valve adjustment amount can be adjusted under different connection pipe lengths;

[0025] If the lag coefficient is less than the first lag value, it is determined that the air conditioner is in a stable operation state.

[0026] In some embodiments of the present application, after the opening adjustment cycle of the electronic expansion valve and the single valve adjustment amount are adjusted, compare the magnitude relationship between the lag coefficient of the next cycle and the first lag value until the lag coefficient is less than the first lag value. If the lag coefficient is not less than the first lag value, regulate the opening adjustment cycle of the electronic expansion valve and the target exhaust superheat degree again according to the lag coefficient, and perform this cycle until the lag coefficient is less than the first lag value, and the controller no longer regulates the opening adjustment cycle of the electronic expansion valve and the target exhaust superheat degree.

[0027] In some embodiments of the present application, the outdoor ambient temperature correction coefficient U = K * (Tx - Toutdef ), when the outdoor temperature T outdef is not less than Tx degrees Celsius, U is a non-positive number to reduce the hysteresis coefficient;

[0028] When the temperature of the outdoor environment is less than Tx degrees Celsius, U is a positive number at this time to increase the hysteresis coefficient.

[0029] In some embodiments of the present application, the controller is configured to: preset a superheat constant coefficient J, and the hysteresis coefficient is inversely proportional to the superheat constant coefficient J.

[0030] In some embodiments of the present application, the indoor heat exchanger and the outdoor heat exchanger are respectively connected through a four-way valve and a compressor. The four-way valve includes a first valve port, a second valve port, a third valve port and a fourth valve port. The compressor includes a suction port connected to the first valve port and an exhaust port connected to the third valve port;

[0031] When the indoor heat exchanger functions as an evaporator, the first valve port is connected to the second valve port, and the third valve port is connected to the fourth valve port;

[0032] When the indoor heat exchanger functions as a condenser, the first valve port is connected to the fourth valve port, and the second valve port is connected to the third valve port.

[0033] In some embodiments of the present application, the controller is configured to: preset an electronic expansion valve opening adjustment period, and control the opening of the electronic expansion valve within an electronic expansion valve opening adjustment period and the time of maintaining different openings according to the electronic expansion valve opening adjustment period; the length of the connecting pipe is L, and 6 m ≤ L ≤ 50 m.

[0034] In some embodiments of the present application, the controller is configured to: calculate the target compressor frequency or the rotational speed of the indoor fan or the rotational speed of the outdoor fan according to the hysteresis coefficient, so that after the instruction of the air conditioner is issued, the controller adjusts the operating state of the compressor or the outdoor fan or the indoor fan according to the operating state of the air conditioner under the specific long connecting pipe.

[0035] The present application has at least the following positive effects:

[0036] The present application provides an air conditioner. The air conditioner includes an indoor unit, which includes an indoor heat exchanger, and an outdoor unit, which includes an outdoor heat exchanger and a compressor. The compressor includes a suction port, a discharge port, and a compression chamber communicating with the suction port and the discharge port, so that the refrigerant entering the compression chamber from the suction port is discharged from the discharge port after being compressed by the compressor. It further includes an electronic expansion valve and a four-way valve, which are connected to the indoor heat exchanger, the outdoor heat exchanger, and the compressor, and are used to switch the air conditioner between a cooling mode and a heating mode. The connecting pipe is connected between the indoor heat exchanger and the outdoor heat exchanger. The controller is configured to calculate the difference C1 between the current discharge superheat and the discharge superheat m electronic expansion valve opening adjustment cycles ago, and the difference C2 between the current suction superheat and the suction superheat m electronic expansion valve opening adjustment cycles ago. The preset lag coefficient is proportional to (C1 + C2). The electronic expansion valve opening adjustment cycle is proportional to the lag coefficient, so that the opening adjustment cycle of the electronic expansion valve is associated with the lag coefficient, making the operation of the air conditioner more stable, enabling the air conditioner to adapt to the setting of a longer connecting pipe, and enabling the air conditioner to operate at a higher efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0038] Figure 1 System schematic diagram of the air conditioner according to the embodiment of the present application when the indoor heat exchanger is used as an evaporator and the outdoor heat exchanger is used as a condenser;

[0039] Figure 2 System schematic diagram of the air conditioner according to the embodiment of the present application when the indoor heat exchanger is used as a condenser and the outdoor heat exchanger is used as an evaporator;

[0040] Figure 3 Flow chart of calculating the lag coefficient of the air conditioner according to the embodiment of the present application;

[0041] Figure 4 Flow chart of calculating the lag coefficient of the air conditioner according to the embodiment of the present application and regulating the opening adjustment cycle of the electronic expansion valve;

[0042] Figure 5 Flow chart of calculating the lag coefficient of the air conditioner according to the embodiment of the present application and determining whether the air conditioner is operating stably;

[0043] Figure 6 General flow chart of the air conditioner with a connecting pipe according to the embodiment of the present application for regulating system parameters through the lag coefficient;

[0044] In the above figures: 100, air conditioner; 1, indoor heat exchanger; 2, outdoor heat exchanger; 3, electronic expansion valve; 4, pipeline; 41, connecting pipe; 51, first temperature sensor; 52, second temperature sensor; 6, compressor; 7, four-way valve; 71: second valve port; 72, second valve port; 73, third valve port; 74, fourth valve port. Specific Embodiments

[0045] Next, the present invention will be specifically described through exemplary embodiments. However, it should be understood that, without further elaboration, the elements, structures, and features in one embodiment can also be beneficially incorporated into other embodiments.

[0046] In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional 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 thus should not be construed as a limitation to the present invention.

[0047] The terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In the following, reference will be made to the attached Figure 1-6 The embodiments of the present application will be described in detail.

[0050] The air conditioner 100 of the present application includes an indoor unit of the air conditioner 100 and an outdoor unit of the air conditioner 100. The outdoor unit of the air conditioner 100 includes a compressor 6 and an outdoor heat exchanger 2. The indoor unit of the air conditioner 100 includes an indoor heat exchanger 1. The electronic expansion valve 3 can be arranged in the indoor unit of the air conditioner 100 or the outdoor unit of the air conditioner 100.

[0051] The indoor heat exchanger 1 and the outdoor heat exchanger 2 can be used as a condenser and an evaporator. When the indoor heat exchanger 1 is used as a condenser, the air conditioner 100 serves as a heater in the heating mode. At this time, the outdoor heat exchanger 2 is an evaporator, and the heat outdoors is released into the indoor space through a vapor compression cycle to achieve the effect of heating the indoor environment. When the indoor heat exchanger 1 is used as an evaporator, the air conditioner 100 serves as a cooler in the cooling mode. At this time, the outdoor heat exchanger 2 is a condenser, so that the heat indoors is released into the outdoor environment through a vapor compression cycle, thereby realizing the cooling effect on the indoor space.

[0052] The compressor 6 includes a suction port, a discharge port, and a compression chamber communicating with the suction port and the discharge port, so that the refrigerant entering the compression chamber from the suction port is compressed by the compressor 6 and discharged from the discharge port. The compressor 6 is used to provide the power for the refrigerant flow in the vapor compression cycle.

[0053] The electronic expansion valve 3 is connected between the indoor heat exchanger 1 and the outdoor heat exchanger 2. The refrigerant flows out of the condenser and then enters the electronic expansion valve 3 for expansion. The electronic expansion valve 3 throttles the high-temperature and high-pressure refrigerant liquid after the condensation process into a low-pressure refrigerant liquid.

[0054] The four-way valve 7 is connected to the indoor heat exchanger 1, the outdoor heat exchanger 2, and the compressor 6, and is used to switch the air conditioner 100 between the cooling condition and the heating condition.

[0055] The pipeline 4 connects the indoor heat exchanger 1, the outdoor heat exchanger 2, the compressor 6, the four-way valve 7, and the electronic expansion valve 3 through the pipeline 4. The pipeline 4 includes an on-line pipe 41: The on-line pipe 41 is connected between the indoor heat exchanger 1 and the outdoor heat exchanger 2, and the length of the on-line pipe 41 is L, where 6 m ≤ L ≤ 50 m.

[0056] The air conditioner 100 performs a refrigeration cycle or a heating cycle through the compressor 6, the condenser, the electronic expansion valve 3, and the evaporator. The refrigeration cycle and the heating cycle include a compression process, a condensation process, an expansion process, and an evaporation process. Through the heat absorption and heat release processes of the refrigerant, cold or heat is provided to the indoor space to achieve the temperature adjustment of the indoor space.

[0057] The compressor 6 compresses the refrigerant gas into a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed high-temperature and high-pressure gaseous refrigerant into a liquid refrigerant, and the heat is released to the surrounding environment through the condensation process.

[0058] The liquid refrigerant flowing out of the condenser enters the electronic expansion valve 3, and the electronic expansion valve 3 expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The low-pressure liquid refrigerant flowing out of the electronic expansion valve 3 enters the evaporator. When the liquid refrigerant flows through the evaporator, it absorbs heat and evaporates into a low-temperature and low-pressure refrigerant gas, and the refrigerant gas in the low-temperature and low-pressure state returns to the compressor 6. The evaporator can achieve a refrigeration effect by using the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. During the entire cycle, the air conditioner 100 can adjust the temperature of the indoor space.

[0059] The air conditioner 100 further includes a first temperature sensor 51 and a second temperature sensor 52. The first temperature sensor 51 is disposed on the pipeline 4 connected to the exhaust port and is used to detect the exhaust temperature of the compressor 6. The second temperature sensor 52 is disposed on the pipeline 4 connected to the suction port and is used to detect the suction temperature of the compressor 6.

[0060] The air conditioner 100 further includes a controller. Both the first temperature sensor 51 and the second temperature sensor 52 are connected to the controller. The first temperature sensor 51 detects the exhaust temperature in real time and uploads it to the controller, and the second temperature sensor 52 detects the suction temperature in real time and uploads it to the controller. The controller calculates the current discharge superheat DSH (n) and the current suction superheat SSH (n) .

[0061] The controller is configured to: when the compressor 6 is running, obtain the current exhaust temperature and the current suction temperature and calculate the current suction superheat SSH (n) and the current discharge superheat DSH (n) ;

[0062] The controller is configured to: preset an electronic expansion valve opening adjustment period, and take the flow time of one cycle of the refrigerant flowing between the suction port and the exhaust port as an electronic expansion valve opening adjustment period, that is, the time required for the refrigerant to flow out of the suction port of the compressor 6 in the air conditioner 100, flow through the indoor heat exchanger 1, the outdoor heat exchanger 2 and the electronic expansion valve 3, and then enter the compression chamber of the compressor 6 and flow out of the exhaust port of the compressor 6 during the entire flow cycle is an electronic expansion valve opening adjustment period, and the electronic expansion valve opening adjustment period is a time threshold.

[0063] The controller is configured to: according to the recorded values of the suction superheat and the discharge superheat, calculate the suction superheat value DSH (n-m) and the discharge superheat value SSH (n-m) before m electronic expansion valve opening adjustment periods.

[0064] The controller is configured to calculate the current discharge superheat DSH (n) and the discharge superheat DSH before the opening adjustment cycles of m electronic expansion valves (n-m) The difference C1, C1 = |DSH (n) - DSH (n-m) |.

[0065] The controller is configured to calculate the current suction superheat SSH (n) and the suction superheat SSH before the opening adjustment cycles of m electronic expansion valves (n-m) The difference C2, C2 = |SSH (n) - SSH (n-m) |.

[0066] The controller is configured to preset a hysteresis coefficient Hys, where Hys is directly proportional to (C1 + C2).

[0067] It should be noted that the larger the sum of C1 and C2, the greater the difference between the current discharge / suction superheat of the air conditioner 100 or the discharge / suction superheat before the opening adjustment cycles of m electronic expansion valves, that is, the air conditioner 100 runs less stably. The controller calculates the hysteresis coefficient, and at this time, the value of the hysteresis coefficient associated with the sum of C1 + C2 is larger, so that the parameter adjustment frequency of the air conditioner 100 is lower, to adapt to the problem that the parameters of the air conditioner 100 respond slower due to the use of a longer connecting pipe, so that the parameters of the air conditioner 100 can fully respond before the next cycle.

[0068] The smaller the sum of C1 and C2, the smaller the difference between the current discharge / suction superheat of the air conditioner 100 or the discharge / suction superheat before the opening adjustment cycles of m electronic expansion valves, that is, the air conditioner 100 runs more stably. The controller calculates the hysteresis coefficient, and at this time, the value of the hysteresis coefficient associated with the sum of C1 + C2 is smaller, so that the parameter adjustment frequency of the air conditioner 100 is faster.

[0069] The controller is configured to regulate the opening adjustment cycle of the electronic expansion valve 3 according to the hysteresis coefficient, and the opening adjustment cycle of the electronic expansion valve 3 is directly proportional to the hysteresis coefficient.

[0070] When the hysteresis coefficient is large, the opening adjustment cycle of the electronic expansion valve 3 is large, so that the adjustment frequency of the electronic expansion valve 3 becomes slower, to cooperate with the problem that the operating parameters of various parts of the air conditioner 100 respond slower due to the longer connecting pipe 41, so that the electronic expansion valve 3 can make the refrigerant fully evaporate or liquefy in the pipeline 4 of the air conditioner 100 and other reactions before the first-stage adjustment, so that the operation of the air conditioner 100 is more stable.

[0071] When the lag coefficient is small, the opening adjustment period of the electronic expansion valve 3 is small, so that the adjustment frequency of the electronic expansion valve 3 becomes faster compared to when the lag coefficient is large. At this time, the degree of lag of the operating parameters at various parts of the air conditioner 100 is small in the case of the relatively long connecting pipe 41. Therefore, the opening adjustment period of the electronic expansion valve 3 is also adjusted to a small extent to match the response degree of the operating parameters at various parts of the air conditioner 100, so that the air conditioner 100 operates more smoothly.

[0072] By positively correlating the lag coefficient with the opening adjustment period of the electronic expansion valve 3, the lag coefficient can reflect the lag degree of the operating parameters at various parts of the air conditioner 100. The opening adjustment period of the electronic expansion valve 3 is regulated according to the lag degree, so that the opening adjustment period of the electronic expansion valve 3 can match the lag degree of the operating parameters at various parts of the air conditioner 100. Thus, after the electronic expansion valve 3 effectively responds to the suction temperature and the discharge temperature after receiving the instruction from the controller, the next opening adjustment period of the electronic expansion valve 3 is carried out, so that the air conditioner 100 can operate stably.

[0073] In the prior art, generally, the length of the connecting pipe 41 of the air conditioner 100 is 5 meters, and the control logic of the parameters of the controller of the air conditioner 100 can only be used for the control logic of the connecting pipe 41 with a length of 5 meters. Due to more protection regulations for building surfaces in some countries now, the outdoor unit of the air conditioner 100 cannot be directly installed on the outside of some buildings. The outdoor unit of the air conditioner 100 can only be installed in a specific storage room for the outdoor unit of the air conditioner 100, resulting in a relatively long distance between the outdoor unit and the indoor unit of the air conditioner 100, and only an extended and extremely long connecting pipe 41 can be used.

[0074] When using an extremely long connecting pipe 41, the length of the connecting pipe 41 will increase to about 50 meters. Due to the increase in the length of the connecting pipe 41, the flow resistance of the refrigerant in the connecting pipe 41 increases, resulting in a decrease in the flow velocity of the refrigerant in the connecting pipe 41 compared to that in the connecting pipe 41 with a length of 5 meters, thereby causing a certain lag in the operating parameters at various parts of the air conditioner 100. Currently, the industry has optimized the control parameters for the extremely long connecting pipe 41. Usually, a fixed correction coefficient is preset to correct the control parameters, and the applicable range of the correction coefficient generally covers the extremely long connecting pipe 41 with a length of 6 meters to 50 meters.

[0075] Since the preset correction coefficient is a fixed value, under different operating states of the air conditioner 100, the correction of the control parameters by the correction coefficient has certain limitations, which will cause the correction coefficient to be unable to effectively correct the control parameters of the air conditioner 100. As a result, even in the case of an extra-long refrigerant pipe, there will still be relatively large problems with the control parameters of the air conditioner 100, which cannot meet the user's requirement that the correction coefficient for the extra-long refrigerant pipe can accurately reflect the influence of the extra-long refrigerant pipe on the control parameters, nor can it meet the user's requirement for the stable operation of the air conditioner 100 with an extra-long refrigerant pipe.

[0076] Compared with the prior art, the hysteresis coefficient in this application is a variable value, and the hysteresis coefficient is related to the current discharge superheat DSH (n) and the discharge superheat DSH before m electronic expansion valve opening adjustment cycles (n-m) The difference C1, the current suction superheat SSH (n) and the suction superheat SSH before m electronic expansion valve opening adjustment cycles (n-3) The difference C2 is related. The sum of C1 and C2 can reflect the degree of hysteresis during the operation of the air conditioner 100. The hysteresis coefficient is proportional to (C1 + C2), so that the hysteresis coefficient can show different values under different operating states during the operation of the air conditioner 100 in different situations. By using the hysteresis coefficient to correct the operating parameters of the components of the air conditioner 100, the air conditioner 100 can operate more smoothly and effectively.

[0077] In some embodiments of this application, the calculation method of the opening adjustment cycle P eev ' of the electronic expansion valve 3 is as follows:

[0078] P' eev = P eev + H ys * R

[0079] In the above formula: P eev ' is the optimized opening adjustment cycle of the electronic expansion valve 3; P eev is the original opening adjustment cycle of the electronic expansion valve 3; Hys is the hysteresis coefficient; R is the opening adjustment calculation constant of the electronic expansion valve 3.

[0080] In some embodiments of this application, the controller is configured to: preset a target discharge superheat that is inversely proportional to the hysteresis coefficient, and regulate the single valve adjustment amount of the electronic expansion valve 3 according to the target discharge superheat, and there is a direct proportional relationship between the target discharge superheat and the single valve adjustment amount. When the hysteresis coefficient is large, the target discharge superheat is lower than the original discharge superheat, thereby reducing the single valve adjustment amount.

[0081] Specifically, the controller is further configured to calculate the target discharge superheat according to the hysteresis coefficient, and then regulate the single valve adjustment amount of the electronic expansion valve 3 according to the target discharge superheat.

[0082] The calculation method of the target exhaust superheat degree is as follows:

[0083] DSH′ obj = DSH obj * H ys / (S + H ys )

[0084] In the above formula, DSH obj ′ is the target exhaust superheat degree after optimization; DSH obj is the original target exhaust superheat degree; S is the calculation constant of the target exhaust superheat degree.

[0085] In some embodiments of the present application, the controller is configured to: preset an outdoor ambient temperature correction coefficient U, the hysteresis coefficient is directly proportional to the outdoor ambient temperature correction coefficient U, and the outdoor ambient temperature correction coefficient U is related to the outdoor ambient temperature constant K and the current outdoor temperature T outdef related.

[0086] In some embodiments of the present application, the calculation method of the outdoor ambient temperature correction coefficient U is as follows:

[0087] U = K * (Tx - T outdef )

[0088] In the above formula, U is the outdoor ambient temperature correction coefficient, K is the outdoor ambient temperature calculation constant and K ≥ 0, T outdef is the current outdoor temperature.

[0089] It should be noted that the units of T outdef and T× are degrees Celsius or Fahrenheit or thermodynamic temperature.

[0090] In some embodiments, T× is 35 degrees Celsius.

[0091] When the temperature of the outdoor environment is not less than 35 degrees Celsius, at this time, the outdoor unit of the air conditioner 100 operates in a high-temperature outdoor environment, the outdoor heat exchanger 2 acts as a condenser and the condensation pressure is relatively high, which is likely to cause the air conditioner 100 to shut down. At this time, it is necessary to make the air conditioner 100 operate at a relatively high frequency. At this time, U is a non-positive number, so that the hysteresis coefficient is reduced, so that the air conditioner 100 can operate at a relatively high frequency.

[0092] When the temperature of the outdoor environment is less than 35 degrees Celsius, at this time, the outdoor unit of the air conditioner 100 operates in an outdoor environment with a relatively low temperature, the outdoor heat exchanger 2 acts as a condenser and the condensation pressure is in a relatively low range, and the risk of the air conditioner 100 shutting down is relatively small. At this time, U is a positive number, so that the hysteresis coefficient is increased, so that the operating parameters of each part of the air conditioner 100 can be stably operated after being corrected by the hysteresis coefficient in the case of a relatively long connecting pipe 41, making the operation of the air conditioner 100 more stable and further reducing the shutdown risk of the air conditioner 100.

[0093] In some embodiments of the present application, the controller is configured to: preset a superheat constant coefficient J, and the hysteresis coefficient is inversely proportional to the superheat constant coefficient J.

[0094] The calculation method of the hysteresis coefficient is as follows:

[0095] H ys =[|DSH (n) -DSH (n-m) |+|SSH (n) -SSH (n-m) |-J]+K*(35 - T outdef )

[0096] In the above formula, Hys is the hysteresis coefficient; DSH (n) is the current exhaust superheat; DSH (n-m) is the exhaust superheat m electronic expansion valve opening adjustment cycles ago; the current suction superheat SSH (n) ; the suction superheat SSH m electronic expansion valve opening adjustment cycles ago (n-m) ; J is the superheat calculation constant; K is the outdoor ambient temperature calculation constant, and T outdef is the current outdoor temperature.

[0097] It should be noted that the unit of T outdef is degrees Celsius, and the unit of 35 in the above formula is also degrees Celsius.

[0098] In some embodiments of the present application, when the air conditioner 100 is started, the controller calculates the hysteresis coefficient, and calculates the opening adjustment cycle and the target exhaust superheat of the electronic expansion valve 3 according to the hysteresis coefficient, so as to regulate the opening adjustment cycle and the valve adjustment amount of a single opening of the electronic expansion valve 3, so that the opening adjustment cycle and the valve adjustment amount of a single opening of the electronic expansion valve 3 can be adjusted under different lengths of the connecting pipe 41, so that the operation of the air conditioner 100 is more stable.

[0099] After the opening adjustment cycle and the target exhaust superheat of the electronic expansion valve 3 are regulated, the controller calculates the hysteresis coefficient of the next cycle again, compares the difference between the hysteresis coefficients of the previous cycle and the next cycle. If the difference is 0, the air conditioner 100 operates stably and there is no need to re-regulate the opening adjustment cycle and the valve adjustment amount of a single opening of the electronic expansion valve 3.

[0100] In some embodiments of the present application, the indoor heat exchanger 1 and the outdoor heat exchanger 2 are respectively connected through a four-way valve 7 and a compressor 6. The four-way valve 7 includes a second valve port 7271, a second valve port, a third valve port 73 and a fourth valve port 74. The compressor 6 includes a suction port connected to the second valve port 7271 and an exhaust port connected to the third valve port 73;

[0101] When the indoor heat exchanger 1 functions as an evaporator, i.e., in the refrigeration mode, the second valve port 7271 is connected to the second valve port, and the third valve port 73 is connected to the fourth valve port 74.

[0102] When the indoor heat exchanger 1 functions as a condenser, i.e., in the heating mode, the second valve port 7271 is connected to the fourth valve port 74, and the second valve port is connected to the third valve port 73. The four-way valve 7 is connected to the controller. The user can switch between the refrigeration mode and the heating mode of the four-way valve 7 by operating the panel connected to the controller, enabling the air conditioner 100 to operate in the refrigeration mode or the heating mode.

[0103] In some embodiments of the present application, the controller is configured to: preset the opening adjustment period of the electronic expansion valve 3, and control the opening of the electronic expansion valve 3 within one opening adjustment period of the electronic expansion valve and the time of maintaining different openings according to the opening adjustment period of the electronic expansion valve 3.

[0104] In some embodiments of the present application, the controller is configured to: preset a first hysteresis value. When the currently calculated hysteresis coefficient obtained by the controller is not less than the first hysteresis value, the controller determines that the operation of the air conditioner 100 fluctuates, continues to detect the current hysteresis coefficient, and recalculates the opening adjustment period of the electronic expansion valve 3 and the target discharge superheat degree, and re-regulates the opening adjustment period and the single valve adjustment amount of the electronic expansion valve 3 to make the operation of the air conditioner 100 more stable.

[0105] When the currently calculated hysteresis coefficient obtained by the controller is less than the first hysteresis value, the controller determines that the operation of the air conditioner 100 is relatively stable, no longer continues to detect the real-time hysteresis coefficient, and continues to operate with the current opening adjustment period of the electronic expansion valve 3 and the target discharge superheat degree, which can maintain the stable operation of the air conditioner 100.

[0106] In some embodiments of the present application, the controller is configured to: calculate the target compressor 6 frequency or the rotational speed of the indoor blower or the rotational speed of the outdoor blower according to the hysteresis coefficient, so that after the instruction of the air conditioner 100 is issued, the operation states of the compressor 6, the outdoor blower, and the indoor blower are regulated according to the specific operation state of the air conditioner 100 under the long connecting pipe, so that the air conditioner 100 can better adapt to the state of the long connecting pipe, and enable the compressor 6, the outdoor blower, and the indoor blower to all operate stably in the hysteresis state.

[0107] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An air conditioner, characterized in that, Comprising: An indoor unit of an air conditioner, which includes an indoor heat exchanger; An outdoor unit of an air conditioner, which includes an outdoor heat exchanger and a compressor. The compressor includes a suction port, a discharge port, and a compression chamber communicating with the suction port and the discharge port, so that the refrigerant entering the compression chamber from the suction port is discharged from the discharge port after being compressed by the compressor; An electronic expansion valve, which is connected between the indoor heat exchanger and the outdoor heat exchanger to throttle the high-temperature and high-pressure refrigerant liquid after the condensation process into a low-pressure refrigerant liquid; A four-way valve, which is connected to the indoor heat exchanger, the outdoor heat exchanger, and the compressor, and is used to switch the air conditioner between a cooling mode and a heating mode; A pipeline, through which the indoor heat exchanger, the outdoor heat exchanger, the compressor, the four-way valve, and the electronic expansion valve are connected. The pipeline includes an on-line pipe: the on-line pipe is connected between the indoor heat exchanger and the outdoor heat exchanger; the length of the on-line pipe is L, and 6m ≤ L ≤ 50m; A first temperature sensor, which is arranged on the pipeline connected to the discharge port and is used to detect the discharge temperature of the compressor; A second temperature sensor, which is arranged on the pipeline connected to the suction port and is used to detect the suction temperature of the compressor; A controller, which is configured to: when the compressor operates, obtain the discharge temperature and the suction temperature and calculate the suction superheat degree and the discharge superheat degree; Taking the flow time of one cycle of the refrigerant flowing between the suction port and the discharge port as an electronic expansion valve opening adjustment period, calculate the suction superheat degree value before m electronic expansion valve opening adjustment periods and the discharge superheat degree value before m electronic expansion valve opening adjustment periods; Calculate the difference C1 between the current discharge superheat degree and the discharge superheat degree before m electronic expansion valve opening adjustment periods, and the difference C2 between the current suction superheat degree and the suction superheat degree before m electronic expansion valve opening adjustment periods. The lag coefficient is proportional to (C1 + C2); According to the lag coefficient and in accordance with the proportional relationship, adjust the electronic expansion valve opening adjustment period, so that the electronic expansion valve opening adjustment period is associated with the flow time of one cycle of the refrigerant flowing between the suction port and the discharge port during the actual operation of the air conditioner.

2. The air conditioner according to claim 1, wherein The controller is configured to: preset a target discharge superheat degree, which is inversely proportional to the lag coefficient, and adjust the single valve adjustment amount of the electronic expansion valve according to the target discharge superheat degree, and the target discharge superheat degree is proportional to the single valve adjustment amount; When the lag coefficient increases, the target discharge superheat degree decreases compared with the original discharge superheat degree, so that the single valve adjustment amount decreases.

3. The air conditioner according to claim 1, wherein The controller is configured to preset an outdoor ambient temperature correction coefficient U, the hysteresis coefficient is proportional to the outdoor ambient temperature correction coefficient U, the outdoor ambient temperature correction coefficient U is proportional to an outdoor ambient temperature constant K, and the outdoor ambient temperature correction coefficient U is inversely proportional to the current outdoor temperature T outdef are inversely proportional.

4. The air conditioner according to claim 2, characterized in that, The controller is configured to: preset a first lag value; When the air conditioner is started for the first time, the controller calculates the lag coefficient and compares the size relationship between the lag coefficient and the first lag value. If the lag coefficient is not less than the first lag value, the opening adjustment period of the electronic expansion valve and the target exhaust superheat degree are recalculated according to the lag coefficient, so that the opening adjustment period of the electronic expansion valve and the single valve adjustment amount can be adjusted under different lengths of the connecting pipes; If the lag coefficient is less than the first lag value, it is determined that the air conditioner is in a stable operation state.

5. The air conditioner according to claim 4, characterized in that, After the opening adjustment period of the electronic expansion valve and the single valve adjustment amount are adjusted, the magnitude relationship between the lag coefficient in the next period and the first lag value is compared again until the lag coefficient is less than the first lag value. If the lag coefficient is not less than the first lag value, the opening adjustment period of the electronic expansion valve and the target exhaust superheat degree are regulated again according to the lag coefficient, and this cycle is carried out until the lag coefficient is less than the first lag value, and the controller no longer regulates the opening adjustment period of the electronic expansion valve and the target exhaust superheat degree.

6. The air conditioner according to claim 3, characterized in that, The outdoor ambient temperature correction coefficient U = K * (35°C - T outdef ), where K is the outdoor ambient temperature calculation constant; when the outdoor temperature T outdef is not less than 35°C, U is a non-positive number to reduce the hysteresis coefficient; When the outdoor temperature T outdef is less than 35°C, U is a positive number at this time to increase the hysteresis coefficient.

7. The air conditioner according to claim 1, characterized in that, The controller is configured to: preset a superheat constant coefficient J, and the lag coefficient is inversely proportional to the superheat constant coefficient J.

8. The air conditioner according to claim 1, characterized in that, The indoor heat exchanger and the outdoor heat exchanger are respectively connected through the four-way valve and the compressor. The four-way valve includes a first valve port, a second valve port, a third valve port and a fourth valve port. The compressor includes a suction port connected to the first valve port and an exhaust port connected to the third valve port; When the indoor heat exchanger acts as an evaporator, 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 indoor heat exchanger acts as a condenser, the first valve port is connected to the fourth valve port, and the second valve port is connected to the third valve port.

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