Air conditioner and control method thereof

Abstract

The application provides an air conditioner and a control method thereof, wherein the air conditioner comprises a compressor, a four-way valve, a condenser, a first throttling device and an evaporator which are connected to form a refrigerant circulation loop; the air conditioner further comprises a second throttling device, one end of the second throttling device is used for being connected to a pipeline between the condenser and the first throttling device, and the other end of the second throttling device is used for being connected to a suction pipeline of the compressor. According to the technical scheme of the application, large flow can be realized, the refrigerant flow under high-temperature working condition is improved, the heat exchange effect of the outdoor condenser is ensured, the adjustment of the indoor and outdoor fan systems can be realized, the indoor and outdoor loads are close to balance, the heat exchange of the whole system is optimal, the system operation state is monitored at any time, adjustment is performed in time, various protection shutdown problems are avoided, the compressor can run in a normal working range, and the service life of the compressor is improved.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning technology, specifically relating to an air conditioner and its control method. Background Technology

[0002] The normal operating temperature of existing air conditioning systems has gradually increased from a maximum of 43℃ in T1 condition to 52℃ in the outer ring of T3, and even higher to 60℃. Currently, the installation space reserved for air conditioners in buildings limits the heat exchange of the outdoor unit, resulting in poor heat dissipation in the environment where the outdoor unit is located, leading to an increase in the ambient temperature. This is a common situation. Ensuring cooling capacity and overall system reliability under extremely high outer ring temperatures (i.e., outdoor unit ambient temperature) has always been a bottleneck and challenge for manufacturers and the industry. Although many products on the market advertise high-temperature cooling, existing technology still has the following problems: the cooling effect of air conditioners under extremely high temperature conditions is not ideal, and the cooling capacity is severely reduced. Extremely high temperature conditions pose a significant challenge to the reliability and stability of the compressor and its system; air conditioners cannot operate continuously under these conditions for extended periods. Summary of the Invention

[0003] Therefore, the present invention provides an air conditioner and its control method, which can solve the problem that the cooling capacity of the air conditioner is severely reduced due to excessively high outdoor ambient temperature in the prior art.

[0004] To address the above problems, the present invention provides an air conditioner comprising a compressor, a four-way valve, a condenser, a first throttling device, and an evaporator connected to form a refrigerant circulation loop;

[0005] The air conditioner also includes a second throttling device, one end of which is used to connect to the pipeline between the condenser and the first throttling device, and the other end of which is used to connect to the suction pipeline of the compressor.

[0006] In some embodiments, the air conditioner further includes a first detection device and a first control device, wherein the first detection device is used to detect the outdoor ambient temperature where the outdoor unit of the air conditioner is located;

[0007] The first control device is used to control the opening and closing of the pipeline of the second throttling device according to the outdoor ambient temperature, so as to control the pipeline of the second throttling device to be closed when the outdoor ambient temperature is less than or equal to T, and to control the pipeline of the second throttling device to be opened when the outdoor ambient temperature is greater than T.

[0008] In some embodiments, the first throttling device is a first throttling valve with an adjustable opening.

[0009] And / or, the second throttling device is a second throttling valve with adjustable opening.

[0010] In some implementations, when the first throttling device is an adjustable throttling valve, the opening of the first throttling valve has M different levels, and the temperature difference ΔTA between the inlet and outlet of the evaporator has M non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening level of the first throttling valve.

[0011] The air conditioner further includes a second detection device and a second control device. The second detection device is used to detect the temperature difference ΔTA between the inlet and outlet of the evaporator. The second control device is used to control the opening of the first throttle valve according to the temperature range of ΔTA, so as to increase the opening of the first throttle valve when ΔTA is in a higher temperature range.

[0012] In some embodiments, the heat exchange fan of the evaporator has M different speed settings, which correspond one-to-one with each temperature range of ΔTA;

[0013] The second control device is further configured to control the fan speed of the evaporator's heat exchange fan according to the temperature range of ΔTA, so as to control the fan speed of the evaporator's heat exchange fan to decrease when ΔTA is in a higher temperature range.

[0014] In some embodiments, the second detection device is used to re-detect the temperature difference ΔTA between the inlet and outlet of the evaporator at time intervals T1;

[0015] The opening degree of the m-th position of the first throttle valve is Am, where m is a positive integer greater than or equal to 1 and less than or equal to M, and Am is greater than A. m-1 The second control device is also used to adjust the opening degree of the first throttle valve at each position according to the number of times n1 of the detection of the temperature difference ΔTA between the inlet and outlet of the evaporator, so that the opening degree Am of the m-th position of the first throttle valve becomes Am', where Am' = Am + ΔA * n1 * (m-1).

[0016] In some implementations, when the second throttling device is an adjustable second throttling valve, the opening of the second throttling valve has R different levels, and the difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening level of the second throttling valve.

[0017] The air conditioner also includes a third detection device and a third control device. The third detection device is used to detect the difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit. The third control device is used to control the opening of the second throttle valve according to the temperature range of ΔTB, so as to increase the opening of the second throttle valve when ΔTB is in a higher temperature range.

[0018] In some embodiments, the heat exchange fan of the condenser has R different speed settings, which correspond one-to-one with each temperature range of ΔTB;

[0019] The third control device is also used to control the fan speed of the condenser's heat exchange fan according to the temperature range of ΔTB, so as to increase the fan speed of the condenser's heat exchange fan when ΔTB is in a higher temperature range.

[0020] In some embodiments, the third detection device is used to re-detect the difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit at every time interval T2.

[0021] The opening degree of the r-th position of the second throttle valve is Br, where r is a positive integer greater than or equal to 1 and less than or equal to R, and Br is greater than B. r-1 The third control device is also used to adjust the opening degree of the second throttle valve at each position according to the number of times n2 of the detection of the difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit, so that the opening degree Br of the r-th position of the second throttle valve becomes Br', where Br' = Br - ΔB * n2 * (r - 1).

[0022] In some embodiments, the air conditioner further includes a gas-liquid separator;

[0023] Wherein, the other end of the second throttling device is connected to the suction line of the compressor through the gas-liquid separator; and / or, the four-way valve has a first connection end for connecting to the suction line of the compressor, the first connection end being connected to the suction line of the compressor through the gas-liquid separator.

[0024] The present invention also provides a control method for an air conditioner. When the first throttling device is an adjustable throttling valve, and the opening of the first throttling valve has M different levels, and the temperature difference ΔTA between the inlet and outlet of the evaporator has M non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening level of the first throttling valve, the control method includes the following adjustment steps for the air conditioner: detecting the temperature difference ΔTA between the inlet and outlet of the evaporator, and controlling the opening level of the first throttling valve according to the temperature range where ΔTA is located, so as to increase the opening level of the first throttling valve when ΔTA is in a higher temperature range;

[0025] And / or, when the second throttling device is an adjustable second throttling valve, and the opening of the second throttling valve has R different levels, and the difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening level of the second throttling valve, the control method includes the following air conditioner adjustment steps: detecting the difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit, and controlling the opening level of the second throttling valve according to the temperature range of ΔTB, so as to control the opening level of the second throttling valve to decrease when ΔTB is in a higher temperature range.

[0026] In some embodiments, when the temperature difference ΔTA between the inlet and outlet of the evaporator has M non-overlapping continuous temperature ranges, and the rotation speed of the heat exchange fan of the evaporator has M different fan speeds that correspond one-to-one with each temperature range of ΔTA, the control method includes the following air conditioner adjustment steps: controlling the fan speed of the heat exchange fan of the evaporator according to the temperature range of ΔTA, so as to control the fan speed of the heat exchange fan of the evaporator to decrease when ΔTA is in a higher temperature range.

[0027] In some implementations, the opening degree of the m-th position of the first throttle valve is Am, where m is a positive integer greater than or equal to 1 and less than or equal to M, and Am is greater than A. m-1 The control method further includes:

[0028] The temperature difference ΔTA between the inlet and outlet of the evaporator is rechecked every time interval T1.

[0029] The opening degree of the first throttle valve is adjusted according to the number of times the temperature difference ΔTA between the inlet and outlet of the evaporator is detected (n1), so that the opening degree Am of the m-th position of the first throttle valve becomes Am', where Am' = Am + ΔA*n1*(m-1).

[0030] In some embodiments, when the difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and the rotation speed of the heat exchange fan of the condenser has R different fan speeds that correspond one-to-one with each temperature range of ΔTB, the control method includes the following air conditioner adjustment steps: controlling the fan speed of the heat exchange fan of the condenser according to the temperature range of ΔTB, so as to increase the fan speed of the heat exchange fan of the condenser when ΔTB is in a higher temperature range.

[0031] In some implementations, the opening degree of the r-th position of the second throttle valve is Br, where r is a positive integer greater than or equal to 1 and less than or equal to R, and Br is greater than B. r-1 The control method further includes:

[0032] The difference ΔTB between the outlet temperature of the condenser and the ambient temperature of the outdoor unit is re-detected every time interval T2.

[0033] The opening degree of the second throttle valve is adjusted according to the number of times n2 is detected based on the difference ΔTB between the condenser outlet temperature and the ambient temperature of the outdoor unit, so that the opening degree Br of the r-th position of the second throttle valve becomes Br', where Br' = Br - ΔB * n2 * (r-1).

[0034] In some implementations, an air conditioner testing step is performed before proceeding to the air conditioner adjustment step, specifically as follows:

[0035] The system detects the outdoor ambient temperature of the outdoor unit of the air conditioner. If the outdoor ambient temperature is greater than T1, the system enters the air conditioner's adjustment step; otherwise, it controls the closure of the second throttling device's pipeline.

[0036] The air conditioner and its control method provided by the present invention have the following beneficial effects:

[0037] 1. Compared to existing technologies where the first throttling device operates alone, resulting in some refrigerant accumulating in the condenser and causing a low refrigerant circulation volume, this invention connects a first throttling device and a second throttling device in parallel after the condenser outlet. The first throttling device is used for normal system throttling, while the second throttling device is used for refrigerant flow regulation. The refrigerant after throttling by the first and second throttling devices is mixed, ensuring that the compressor suction is in a saturated or slightly superheated state. This can increase the system's refrigerant circulation volume, achieve a large flow rate, improve the refrigerant flow rate under high-temperature conditions, ensure the heat exchange effect of the outdoor condenser, and enhance the air conditioner's cooling capacity under excessively high outdoor ambient temperatures.

[0038] 2. By detecting the temperature at the inlet and outlet of the condenser and evaporator, combined with the optimized control logic, the indoor and outdoor fan systems can be adjusted to make the load on both sides of the indoor and outdoor units nearly balanced, ensuring optimal heat exchange of the entire system. At the same time, the operating status of the air conditioning system can be monitored at all times, and timely adjustments can be made to avoid various protection shutdown problems.

[0039] 3. By using dual throttling valves, the refrigerant flow rate after throttling is greater than that after throttling with a single electronic expansion valve. This reduces the compressor's suction specific volume, thereby increasing the refrigerant circulation flow rate. This is beneficial for compressor cooling, allowing the compressor to operate within its normal operating range and extending its service life. Attached Figure Description

[0040] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0041] Figure 1 This is a simplified structural diagram of the air conditioner of the present invention;

[0042] Figure 2 This is the tube temperature control opening logic diagram of the evaporator of the present invention;

[0043] Figure 3 This is the tube temperature control opening logic diagram of the condenser of the present invention;

[0044] Figure 4 This is a partial flowchart of the control method of the present invention;

[0045] Figure 5 This is a pressure-enthalpy diagram of the air conditioner's system operation.

[0046] The attached figures are labeled as follows:

[0047] 01. Compressor; 02. Four-way valve; 03. Condenser branch junction temperature sensor; 04. Condenser outer ring temperature sensor; 05. Condenser heat exchange fan; 06. Condenser; 07. Condenser subcooling outlet temperature sensor; 08. First throttle valve; 09. Second throttle valve; 010. Gas-liquid separator; 011. Evaporator inlet temperature sensor; 012. Evaporator heat exchange fan; 013. Evaporator; 014. Evaporator ambient temperature sensor; 015. Evaporator outlet temperature sensor; 016. Exhaust pipe temperature sensor. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0050] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0051] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of illustrative purposes and to facilitate understanding and reading by those skilled in the art, and are not intended to limit the conditions under which the invention can be implemented. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives achieved by the invention, should still fall within the scope of the technical content disclosed in the invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0052] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0053] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0054] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0055] See also Figure 1 As shown, an air conditioner according to an embodiment of the present invention is provided, which includes a compressor 01, a four-way valve 02, a condenser 06, a first throttling device, and an evaporator 013 connected to form a refrigerant circulation loop. The air conditioner further includes a second throttling device, one end of which is connected to a pipeline between the condenser 06 and the first throttling device, and the other end of which is connected to the suction pipeline of the compressor 01.

[0056] Compared to existing technologies where the first throttling device operates alone, resulting in some refrigerant accumulating in the condenser 06 and causing a low refrigerant circulation volume, this invention connects a first throttling device and a second throttling device in parallel after the outlet of the condenser 06. The first throttling device is used for normal system throttling, while the second throttling device is used for refrigerant flow regulation. The refrigerant throttled by the first and second throttling devices is mixed, ensuring that the compressor 01 intake is in a saturated or slightly superheated state. This increases the system's refrigerant circulation volume, achieves a large flow rate, improves the refrigerant flow under high-temperature conditions, ensures the heat exchange effect of the outdoor condenser 06, and enhances the air conditioner's cooling capacity under excessively high outdoor ambient temperatures.

[0057] The aforementioned air conditioner also includes a first detection device and a first control device. The first detection device is used to detect the outdoor ambient temperature where the outdoor unit of the air conditioner is located. The first control device is used to control the opening and closing of the pipe of the second throttling device according to the outdoor ambient temperature, so as to maintain the outdoor ambient temperature T. 外环When T is less than or equal to T, the pipeline controlling the second throttling device is closed, and the outdoor ambient temperature T 外环 When the temperature is greater than T, the pipeline controlling the second throttling device opens. In a specific application example, T can be 45 degrees Celsius.

[0058] Specifically, when the outdoor ambient temperature is within the normal range, the temperature difference between the condenser 06 and the outdoor ambient temperature is large, resulting in high heat exchange efficiency for the outer condenser 06 and meeting the user's cooling capacity requirements. In this case, the second throttling device can be closed, allowing the first throttling device to operate independently. When the outdoor ambient temperature rises to the load condition, the temperature difference between the condenser 06 and the outdoor ambient temperature becomes smaller, leading to lower heat exchange efficiency for the outer condenser 06 and a decrease in the air conditioner's cooling capacity. In this case, the second throttling device can be opened, allowing both the first and second throttling devices to operate simultaneously. This achieves a larger flow rate, increasing the refrigerant flow under high-temperature conditions, ensuring the heat exchange effect of the outdoor condenser 06, and improving the air conditioner's cooling capacity under excessively high outdoor ambient temperatures.

[0059] It should be noted that the second throttling device mentioned above can be a throttling valve, a capillary tube, etc. When the second throttling device is a throttling valve, the pipeline of the second throttling device can be closed by closing the throttling valve, and the pipeline of the second throttling device can be opened by opening the throttling valve.

[0060] In a specific application example, such as Figure 1 As shown, the aforementioned first throttling device can be a first throttling valve 08 with adjustable opening. The second throttling device can be a second throttling valve 09 with adjustable opening. Both the first throttling valve 08 and the second throttling valve 09 can be electronic expansion valves, etc.

[0061] In a specific application example, when the first throttling device is an adjustable throttling valve 08, the opening of the first throttling valve 08 has M different levels, and the temperature difference ΔTA between the inlet and outlet of the evaporator 013 has M non-overlapping continuous temperature ranges, with each temperature range corresponding one-to-one with the opening level of the first throttling valve 08. The air conditioner also includes a second detection device and a second control device. The second detection device detects the temperature difference ΔTA between the inlet and outlet of the evaporator 013, and the second control device controls the opening level of the first throttling valve 08 according to the temperature range of ΔTA, so that when ΔTA is in a higher temperature range, the opening level of the first throttling valve 08 is increased.

[0062] like Figure 1As shown, the aforementioned second detection device includes an evaporator inlet temperature sensor 011, an evaporator ambient temperature sensor 014, and an evaporator outlet temperature sensor 015. The evaporator inlet temperature sensor 011 is used to detect the inlet temperature TA1 of the evaporator 013, and the evaporator outlet temperature sensor 015 is used to detect the outlet temperature TA2 of the evaporator 013. The temperature difference between the inlet and outlet of the evaporator 013, ΔTA, is calculated as |TA1 - TA2|.

[0063] In the example above, the larger the temperature difference ΔTA between the inlet and outlet of evaporator 013, the more insufficient the refrigerant in evaporator 013 is, indicating that the heat exchange area of ​​evaporator 013 is excessive. It is necessary to increase the refrigerant circulation flow rate, which requires increasing the opening of the first throttle valve 08. This allows more refrigerant to flow into evaporator 013, improving the utilization rate of the heat exchange area and making heat exchange within the heat exchanger more efficient.

[0064] Furthermore, the aforementioned evaporator's heat exchange fan 012 has M different fan speeds, each corresponding to a temperature range of ΔTA. The second control device is also used to control the fan speed of the evaporator's heat exchange fan 012 according to the temperature range of ΔTA, so as to lower the fan speed of the evaporator's heat exchange fan 012 when ΔTA is in a higher temperature range.

[0065] In the example above, the larger the temperature difference ΔTA between the inlet and outlet of the evaporator 013, the greater the heat exchange capacity of the indoor evaporator 013 will be by reducing the fan speed of the heat exchange fan 012 of the evaporator. The temperature difference between the inlet and outlet of the evaporator 013 will also be smaller. This can further improve the utilization rate of the heat exchange area of ​​the evaporator 013, making the heat exchange in the heat exchanger more complete.

[0066] The purpose of adjusting the opening of the first throttle valve 08 and the speed of the heat exchange fan 012 of the evaporator is to match the amount of refrigerant in the indoor evaporator 013 with the heat exchange area of ​​the evaporator 013, so as to avoid insufficient utilization of the heat exchange area, maximize the use of evaporation for heat exchange, improve the heat exchange efficiency of the heat exchanger, and ensure that the evaporator 013 is in the best working condition.

[0067] like Figure 2 As shown, the aforementioned second detection device is used to re-detect the temperature difference ΔTA between the inlet and outlet of the evaporator 013 at intervals T1. In a specific application example, T1 can be 55-65 seconds, preferably 60 seconds, and can be determined according to the actual situation.

[0068] The opening degree of the m-th position of the aforementioned first throttle valve 08 is Am, where m is a positive integer greater than or equal to 1 and less than or equal to M, and Am is greater than A. m-1That is, the opening degree of the m-th position of the first throttle valve 08 is greater than the opening degree of the (m-1)-th position. The aforementioned second control device is also used to adjust the opening degree of the first throttle valve 08 at each position according to the number of times n1 of the detection of the temperature difference ΔTA between the inlet and outlet of the evaporator 013, so that the opening degree Am of the m-th position of the first throttle valve 08 becomes Am', where Am' = Am + ΔA*n1*(m-1).

[0069] In the above example, the opening degree of the first position of the first throttle valve 08 is A1, and A1' is always equal to A1. The temperature range corresponding to the temperature difference ΔTA at the first position of the first throttle valve 08 is the target temperature range. The opening degrees of the other positions of the first throttle valve 08, except for the first position, will change with the number of detections n1 to adjust the temperature difference between the inlet and outlet of the evaporator 013, so that the temperature difference ΔTA between the inlet and outlet of the evaporator 013 is as close as possible to or falls within the target temperature range. When the temperature difference ΔTA between the inlet and outlet of the evaporator 013 is within the target temperature range, the heat exchange of the evaporator 013 is optimal, and the compressor 01 can operate within its normal working range, thereby extending the service life of the compressor 01.

[0070] In a specific application example, M is 3, meaning the first throttle valve 08 has three settings, A1, A2, and A3. The temperature difference ΔTA between the inlet and outlet of the evaporator 013 has three non-overlapping continuous temperature ranges, namely range 1, range 2, and range 3. The heat exchange fan 012 of the evaporator has three different speed settings: high, medium, and low. In one example, the range 1 of the temperature difference ΔTA is (0, 2.5], the range 2 is (2.5, 5], and the range 3 is (5, ∞), A1=200B, A2=235B, A3=255B, and ΔA=10B. Here, B, or step, is the unit of opening of the first throttle valve 08; 200B means 200 steps. The first throttle valve 08 can be an electronic expansion valve, and the opening range of an electronic expansion valve is generally 0B~500B.

[0071] The process begins with selecting the corresponding operating interval based on the range of ΔTA, according to the program settings—this is the first judgment, and n1 is recorded as 1. After the initial interval selection, the initial opening and damper of the corresponding first throttle valve 08 are adjusted, with the opening of the first throttle valve 08 set to A1, A2, or A3. After a time interval T1, for example, 60 seconds, a second check is performed, and n1 is recorded as 2. The new interval is confirmed, and the opening of each interval is updated to A1', A2', or A3' (the initial adjustment of the opening of the first throttle valve 08, A1, A2, or A3, will be replaced by A1', A2', or A3'). The opening and damper of the first throttle valve 08 are then readjusted based on the adjusted interval values. Subsequent interval checks are performed every T1 interval, and the count is incremented by n1 for each check. The corresponding A1', A2', or A3' values ​​are updated repeatedly in this manner.

[0072] For example, upon initial startup, if the system meets the requirements for entering the high-temperature cooling control logic, and the first detected ΔTA range is range 2 (i.e., the ΔT temperature difference value is within the range of 2.5 and 5), then the opening of the first throttle valve 08 needs to be adjusted from the previously calculated opening to the A2 opening (here, 235B). The fan speed should be adjusted to medium (adjust if the user-set speed is lower than medium; otherwise, maintain the user-set speed). After continuous operation for T1, the ΔTA temperature difference value should be detected again. This is recorded as the second detection, and the detection should be performed simultaneously. The count is incremented by 1 for each test (n1). Based on the ΔTA temperature difference value from n1 tests and the set range, a new operating range and a new opening value for the first throttle valve 08 are determined. For example, after the second test, if the updated ΔTA temperature difference value is within the range of (0, 2.5), i.e., within range 1, then the opening of the first throttle valve 08 is adjusted to A1' (where A1' = A1 = 200B), and the fan speed is adjusted to high. The program is then repeated until a shutdown command is issued.

[0073] In a specific application example, when the second throttling device is an adjustable second throttling valve 09, the opening degree of the second throttling valve 09 has R different levels. The difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening degree of the second throttling valve 09. The air conditioner also includes a third detection device and a third control device. The third detection device is used to detect the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit. The third control device is used to control the opening degree of the second throttling valve 09 according to the temperature range of ΔTB, so that when ΔTB is in a higher temperature range, the opening degree of the second throttling valve 09 is increased.

[0074] The heat exchange capacity and heat exchange area utilization of the condenser 06 inside the outdoor unit depend on the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit. The smaller the difference ΔTB, the better the heat exchange of the condenser 06. The larger the difference ΔTB, the more refrigerant is in the condenser 06, the higher the pressure, and the higher the exhaust temperature. In this case, by opening the bypass second throttle valve 09 and increasing its opening position, the heat exchange capacity of the condenser 06 can be increased, while the pressure of the outer condenser 06 and the exhaust temperature of the compressor 01 can be reduced, thus avoiding shutdown due to high temperature conditions.

[0075] like Figure 1 As shown, the aforementioned third detection device includes a condenser branch temperature sensor 03, a condenser outer ring temperature sensor 04, and a condenser subcooling outlet temperature sensor 07. The condenser outer ring temperature sensor 04 detects the ambient temperature TB1 of the outdoor unit, and the condenser subcooling outlet temperature sensor 07 detects the outlet temperature TB2 of the condenser 06. The difference between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit is ΔTB = |TB1 - TB2|.

[0076] It should be noted that the exhaust pipe of compressor 01 is also equipped with an exhaust pipe temperature sensor 016, which is used to detect the exhaust temperature of compressor 01.

[0077] Furthermore, the heat exchange fan 05 of the aforementioned condenser 06 has R different fan speeds, each corresponding to a temperature range of ΔTB. For example, Figure 3 As shown, the third control device is also used to control the fan speed of the heat exchange fan 05 of the condenser 06 according to the temperature range of ΔTB, so as to increase the fan speed of the heat exchange fan 05 of the condenser 06 when ΔTB is in a higher temperature range.

[0078] In the above example, the larger the difference ΔTB between the outlet temperature of condenser 06 and the ambient temperature of the outdoor unit, the greater the airflow of the heat exchange fan 05 of condenser 06 can be, by increasing the fan speed of the heat exchange fan 05, thereby increasing the heat exchange of condenser 06. This can further increase the heat of condenser 06, while further reducing the pressure of the outer condenser 06 and the exhaust temperature of compressor 01, thus avoiding shutdown under high temperature conditions.

[0079] like Figure 3 As shown, the aforementioned third detection device is used to re-detect the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit at time intervals T2. In a specific application example, T2 can be 55-65 seconds, preferably 60 seconds, and can be determined according to the actual situation.

[0080] The opening degree of the r-th position of the aforementioned second throttle valve 09 is Br, where r is a positive integer greater than or equal to 1 and less than or equal to R, and Br is greater than B. r-1 That is, the opening degree of the second throttle valve 09 at position r is greater than the opening degree of position r-1. The third control device is also used to adjust the opening degree of the second throttle valve 09 at each position according to the number of times n2 of the detection of the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit, so that the opening degree Br of the second throttle valve 09 at position r becomes Br', where Br' = Br - ΔB * n2 * (r-1).

[0081] In the above example, the opening degree of the first position of the second throttle valve 09 is B1, and B1' is always equal to B1. The temperature range corresponding to the temperature difference ΔTB of the first position of the second throttle valve 09 is the target temperature range. The opening degrees of the other positions of the second throttle valve 09, except for the first position, will change with the number of detections n2 to adjust the temperature difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit, so that the temperature difference ΔTB is as close as possible to or falls within the target temperature range. When the temperature difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit is within the target temperature range, the heat exchange of the condenser 06 is optimal, and the compressor 01 can operate within its normal working range, thereby extending the service life of the compressor 01.

[0082] In a specific application example, R is 3, meaning the second throttle valve 09 has three positions, namely B1, B2, and B3. The difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit has three non-overlapping continuous temperature ranges, namely range 1, range 2, and range 3. In one example, range 1 of the difference ΔTB is (0, 4], range 2 is (4, 7], and range 3 is (7, ∞), with B1=150B, B2=185B, B3=205B, and ΔB=15B.

[0083] In a specific application example, based on the range of ΔTB, the corresponding operating range is selected according to the program settings—this is the first judgment. n2 is recorded as 1. After the initial range selection, the initial opening and damper of the corresponding second throttle valve 09 are adjusted, and the opening of the second throttle valve 09 is B1, B2, or B3. After a time T2, for example, 60 seconds, a second check is performed, and n2 is recorded as 2. The new range is confirmed, and the opening of each range is updated to B1', B2', or B3' (the valve opening B1, B2, or B3 adjusted in the first check will be replaced by B1', B2', or B3'). The opening and damper of the second throttle valve 09 are readjusted according to the adjusted range values. Subsequently, a range check is performed every T2 interval, and the count n2 is incremented for each check. The corresponding B1', B2', or B3' values ​​are updated repeatedly.

[0084] For example, upon initial startup, if the system meets the requirements for entering the high-temperature cooling control logic, and the first detected ΔTB range is range 2 (i.e., the ΔTB temperature difference value is within the range of 4 and 7), then the opening of the second throttle valve 09 needs to be adjusted from 0B to B2 (here, 185B). The speed of the heat exchange fan 05 of the condenser 06 should be increased by one level from the current speed (the initial speed of the heat exchange fan 05 of the condenser 06 is the original program execution speed; if the speed of the heat exchange fan 05 of the condenser 06 is already at the highest speed and there is no room for further increase, then the current speed should be maintained). After continuous operation for T2, the ΔTB temperature... Difference detection. This is recorded as the second detection, and the number of detections (n2) is counted simultaneously. Each detection increments the count by 1. Based on the ΔTB temperature difference value from the n2 detections and the set range, a new operating range and a new opening value for the second throttle valve 09 are determined. For example, after the second detection, if the updated ΔTB temperature difference value is within the range (0, 4), i.e., within range 1, then the opening of the second throttle valve 09 is adjusted to B1' (at this point, B1' = B1 = 150B opening), while the fan speed remains unchanged. The procedure is repeated until a shutdown command is issued.

[0085] like Figure 1 As shown, the aforementioned air conditioner also includes a gas-liquid separator 010, wherein the other end of the second throttling device is connected to the suction line of the compressor 01 via the gas-liquid separator 010. And / or, the four-way valve 02 has a first connection end for connecting to the suction line of the compressor 01, which is connected to the suction line of the compressor 01 via the gas-liquid separator 010.

[0086] The gas-liquid separator 010 can be a three-pipe system. The pipe after throttling by the second throttling device is inserted into the lower part of the partition of the gas-liquid separator 010, while the inlet of the compressor 01's suction pipe is located at the upper part of the partition. The volume of the gas-liquid separator 010 is calculated based on the difference between the theoretical refrigerant capacity for high-temperature refrigeration and the theoretical refrigerant capacity for normal-temperature refrigeration. The volume of the gas-liquid separator 010 is selected such that the liquid refrigerant volume occupies 0.5 to 0.6 of the pipe volume to avoid liquid carryover during suction. The space above the partition and the gas-liquid separator 010 occupies approximately 0.2 of the total volume.

[0087] In the above example, by connecting the gas-liquid separator 010 in series in the air conditioning system, the suction state of the compressor 01 can be stabilized, avoiding excessively high discharge temperature of the compressor 01 caused by excessive suction overheating.

[0088] It should be noted that the aforementioned first control device, second control device and third control device can be the same control device, such as a processor or PLC.

[0089] like Figure 2 and Figure 3 As shown, the present invention also provides a control method for the above-mentioned air conditioner. When the first throttling device is an adjustable first throttling valve 08, and the opening of the first throttling valve 08 has M different levels, and the temperature difference ΔTA between the inlet and outlet of the evaporator 013 has M non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening level of the first throttling valve 08, the control method includes the following adjustment steps for the air conditioner: detecting the temperature difference ΔTA between the inlet and outlet of the evaporator 013, and controlling the opening level of the first throttling valve 08 according to the temperature range where ΔTA is located, so as to increase the opening level of the first throttling valve 08 when ΔTA is in a higher temperature range.

[0090] The larger the temperature difference ΔTA between the inlet and outlet of evaporator 013, the more insufficient the refrigerant in evaporator 013, indicating an excess heat exchange area. It is necessary to increase the refrigerant circulation flow rate, which requires increasing the opening of the first throttle valve 08. This allows more refrigerant to flow into evaporator 013, improving the utilization rate of the heat exchange area and ensuring more efficient heat exchange within the heat exchanger.

[0091] When the second throttling device is an adjustable second throttling valve 09, and the opening of the second throttling valve 09 has R different levels, and the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening level of the second throttling valve 09, the control method includes the following adjustment steps for the air conditioner: detecting the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit, and controlling the opening level of the second throttling valve 09 according to the temperature range of ΔTB, so as to control the opening level of the second throttling valve 09 to decrease when ΔTB is in a higher temperature range.

[0092] The heat exchange capacity and heat exchange area utilization of the condenser 06 inside the outdoor unit depend on the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit. The smaller the difference ΔTB, the better the heat exchange of the condenser 06. The larger the difference ΔTB, the more refrigerant is in the condenser 06, the higher the pressure, and the higher the exhaust temperature. In this case, by opening the bypass second throttle valve 09 and increasing its opening position, the heat exchange capacity of the condenser 06 can be increased, while the pressure of the outer condenser 06 and the exhaust temperature of the compressor 01 can be reduced, thus avoiding shutdown due to high temperature conditions.

[0093] Furthermore, when the temperature difference ΔTA between the inlet and outlet of the evaporator 013 has M non-overlapping continuous temperature ranges, and the rotation speed of the heat exchange fan 012 of the evaporator has M different fan speeds that correspond one-to-one with each temperature range of ΔTA, the aforementioned control method may include the following air conditioner adjustment steps: controlling the fan speed of the heat exchange fan 012 of the evaporator according to the temperature range of ΔTA, so as to control the fan speed of the heat exchange fan 012 of the evaporator to decrease when ΔTA is in a higher temperature range.

[0094] In the example above, the larger the temperature difference ΔTA between the inlet and outlet of the evaporator 013, the greater the heat exchange capacity of the indoor evaporator 013 will be by reducing the fan speed of the heat exchange fan 012 of the evaporator. The temperature difference between the inlet and outlet of the evaporator 013 will also be smaller. This can further improve the utilization rate of the heat exchange area of ​​the evaporator 013, making the heat exchange in the heat exchanger more complete.

[0095] The opening degree of the m-th position of the aforementioned first throttle valve 08 is Am, where m is a positive integer greater than or equal to 1 and less than or equal to M, and Am is greater than A. m-1The aforementioned control method also includes: re-detecting the temperature difference ΔTA between the inlet and outlet of the evaporator 013 at intervals T1; adjusting the opening degree of the first throttle valve 08 at each position according to the number of detections n1 of the temperature difference ΔTA between the inlet and outlet of the evaporator 013, so that the opening degree Am of the m-th position of the first throttle valve 08 becomes Am', where Am' = Am + ΔA * n1 * (m-1).

[0096] Because the refrigerant in the air conditioning system is constantly flowing and the indoor ambient temperature changes over time, it is necessary to update the opening of the first throttle valve 08 and the speed of the heat exchange fan 012 of the evaporator every certain period of time, so that the amount of refrigerant in the indoor evaporator 013 and the heat exchange area of ​​the evaporator 013 are as coordinated as possible.

[0097] Furthermore, when the temperature difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and the rotation speed of the heat exchange fan 05 of the condenser 06 has R different fan speeds that correspond one-to-one with each temperature range of ΔTB, the aforementioned control method may include the following air conditioner adjustment steps: controlling the fan speed of the heat exchange fan 05 of the condenser 06 according to the temperature range of ΔTB, so as to increase the fan speed of the heat exchange fan 05 of the condenser 06 when ΔTB is in a higher temperature range.

[0098] In the above example, the larger the difference ΔTB between the outlet temperature of condenser 06 and the ambient temperature of the outdoor unit, the greater the airflow of the heat exchange fan 05 of condenser 06 can be, by increasing the fan speed of the heat exchange fan 05, thereby increasing the heat exchange of condenser 06. This can further increase the heat of condenser 06, while further reducing the pressure of the outer condenser 06 and the exhaust temperature of compressor 01, thus avoiding shutdown under high temperature conditions.

[0099] The opening degree of the r-th position of the aforementioned second throttle valve 09 is Br, where r is a positive integer greater than or equal to 1 and less than or equal to R, and Br is greater than B. r-1 The aforementioned control method further includes: re-detecting the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit at every time interval T2; adjusting the opening degree of the second throttle valve 09 at each position according to the number of detections n2 of the difference ΔTB between the outlet temperature of the condenser 06 and the ambient temperature of the outdoor unit, so that the opening degree Br of the r-th position of the second throttle valve 09 becomes Br', where Br' = Br - ΔB * n2 * (r-1).

[0100] Because the refrigerant in the air conditioning system is constantly flowing and the outdoor ambient temperature is also changing over time, it is necessary to update the opening of the second throttle valve 09 and the speed of the heat exchange fan 05 of the condenser 06 every once in a while, so that the amount of refrigerant in the condenser 06 and the heat exchange area of ​​the condenser 06 are as coordinated as possible.

[0101] Furthermore, before entering the air conditioner's adjustment steps, a detection step is performed. Specifically, this involves detecting the outdoor ambient temperature where the outdoor unit is located. If the outdoor ambient temperature is greater than T, the air conditioner's adjustment steps are initiated; otherwise, the second throttling device's piping is closed. In other words, if the outdoor ambient temperature T... 外环 When the outdoor ambient temperature is greater than T, the air conditioner enters the high-temperature cooling control logic, i.e., logic II. Under logic II, the second throttle valve 09 opens and operates according to the logic control. If the outdoor ambient temperature T... 外环 If T is less than or equal to T, then logic I is entered, which means the existing default procedure is followed without any changes. Under logic I, only the first throttle valve 08 is operational, the pipeline of the second throttle valve 09 is closed, and the second throttle valve 09 is also closed. In a specific application example, T can be 45 degrees.

[0102] In the example above, when the outdoor ambient temperature is within the normal temperature range, i.e., the outdoor ambient temperature T... 外环 When the temperature is less than or equal to T, the temperature difference between the condenser 06 and the outdoor ambient temperature is relatively large, the heat exchange efficiency of the outer condenser 06 is high, and the cooling capacity of the air conditioner meets the user's development needs. At this time, the pipe of the second throttling device can be closed, allowing the first throttling device to operate independently. When the outdoor ambient temperature T... 外环 Increase to the load condition, i.e., outdoor ambient temperature T 外环 When the temperature is greater than T, the temperature difference between the condenser 06 and the outdoor ambient temperature is small, the heat exchange efficiency of the outer condenser 06 is low, and the cooling capacity of the air conditioner decreases. At this time, the pipe of the second throttling device can be opened, so that the first throttling device and the second throttling device work at the same time. This can achieve a large flow rate, increase the refrigerant flow rate under high temperature conditions, ensure the heat exchange effect of the outdoor condenser 06, and improve the cooling capacity of the air conditioner under excessively high outdoor ambient temperature conditions.

[0103] It should be noted here that: (as...) Figure 3 As shown, before entering the air conditioner's testing step, the air conditioner first enters the start-up preheating step. Specifically, after receiving the start-up command, the air conditioner performs a self-test and, if no problems are found, executes the start-up program. After the test is successful, the air conditioner enters the air conditioner testing step after running for the default program time T3. T3 can be 200s-280s, preferably 240s.

[0104] For ease of understanding, the overall structure of the present invention will be described below, and its working principle will be explained. Figure 5 Taking the system working pressure-enthalpy diagram as an example, the system working process of the air conditioner of the present invention is briefly described as follows: Under normal outer ring working temperature, the circulation process of the whole system is: 1→1'→2→3→4→5→6→1.

[0105] Wherein, 1→1': Under the refrigeration state, the refrigerant vapor evaporated in the evaporator 013 changes from the low temperature and low pressure saturated state 1 to the low pressure and superheated state 1'.

[0106] 1'→2: During the intake and compression process of compressor 01, the low-pressure superheated gaseous state 1' is compressed into a high-temperature and high-pressure gaseous state 2.

[0107] 2→3→4→5: The exhaust gas from compressor 01 is cooled to a high temperature and high pressure saturated gas state 3, which is then condensed in condenser 06 to become a medium temperature saturated liquid state 4, and then cooled again to become a subcooled liquid state 5.

[0108] 5→6: The high-temperature and high-pressure refrigerant passing through the outlet of condenser 06 is throttled and becomes a low-temperature and low-pressure gas-liquid mixture 6, which then evaporates and absorbs heat in evaporator 013.

[0109] 6→1: The low-temperature, low-pressure gas-liquid mixed refrigerant undergoes saturated evaporation in evaporator 013 to become saturated gas.

[0110] During this process, the outer ring temperature is within the normal temperature range. At this time, the temperature difference between the condensing temperature and the ambient temperature is relatively large, resulting in high heat exchange efficiency for the outer condenser (06). The cooling capacity also meets the user's development requirements. At this point, the electronic expansion valve only controls valve A, while valve B is closed. The unit cooling capacity is H1'-H6.

[0111] Under high external ring temperature conditions, the overall system circulation process is: 8→9→3'→4'→10→11→1→1'→8 plus 8→9→3'→4'→10→12→7→8; the two processes are superimposed. Because the external ring temperature rises to an overload condition, if the saturation temperature of condenser 06 is still the normal condenser 06 temperature, the heat exchange efficiency of condenser 06 will decrease. Therefore, it is necessary to increase the condensing temperature of condenser 06 to ensure the heat exchange of the outdoor condenser 06. At the same time, since the heat exchange area of ​​condenser 06 remains unchanged, the subcooling of condenser 06 should be smaller than or even non-existent under normal operating conditions. If the evaporator end still needs to reach the 1' point suction, the discharge temperature of compressor 01 will inevitably exceed the discharge temperature under normal operating conditions. At this time, compressor 01 discharge protection or frequency reduction due to excessively high discharge temperature is likely to occur. By adding the throttling process of valve B (8→9→3'→4'→10→12→7→8), the suction temperature can be controlled by mixing the low-temperature refrigerant after throttling with the outlet gas of evaporator 013, indirectly controlling the discharge temperature to prevent it from exceeding the normal operating temperature too much. At this point, the unit cooling capacity is H8-H12, which is a reduction of H11-H6 and H1'-H8 compared to the normal operating capacity of H1'-H6.

[0112] Therefore, theoretically, under high-temperature refrigeration conditions, the refrigeration capacity will decrease. However, the solution of this invention can increase the refrigerant flow rate in the system per unit time and reduce the suction temperature through dual throttling valves, thereby ensuring that the suction is saturated or slightly superheated as much as possible. This allows the compressor's 01 frequency to be maintained or even increased, minimizing the decrease in refrigeration capacity under high-temperature refrigeration conditions, thus ensuring the refrigeration capacity and achieving reliable and stable system operation.

[0113] Furthermore, this invention, through temperature detection by the inlet and outlet temperature sensors of the condenser 06 and evaporator 013, combined with optimized control logic, can regulate the indoor and outdoor fan systems, ensuring a near-balanced load between the indoor and outdoor units. This guarantees optimal heat exchange for the entire system. Simultaneously, it can continuously monitor the system's operating status and make timely adjustments to prevent various protective shutdowns.

[0114] By using the temperature difference between the tube and ambient temperatures of condenser 06 and the inlet and outlet temperature sensors of evaporator 013, logical judgments are made. By judging the heat exchange status of condenser 06 and evaporator 013, the fan speeds of the internal and external fan systems are adjusted in a timely manner to improve the heat exchange efficiency of the heat exchangers and ensure that the heat exchangers are in the best working condition.

[0115] This invention utilizes dual throttling valves for throttling control, resulting in a larger refrigerant flow rate after throttling compared to single throttling valves. This reduces the suction specific volume of compressor 01, thereby increasing the refrigerant circulation flow rate. This benefits the cooling of compressor 01, allowing it to operate within its normal operating range and extending its service life. Furthermore, optimized opening control logic enables precise adjustment of the two throttling valves, controlling the suction volume and suction temperature range of compressor 01. This ensures compressor 01 operates within its optimal range, guaranteeing its reliability. Simultaneously, it ensures the stability of the entire system, preventing damage caused by frequent start-ups and shutdowns of system components.

[0116] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0117] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. An air conditioner, characterized in that: Includes a compressor (01), a four-way valve (02), a condenser (06), a first throttling device, and an evaporator (013) that are connected to form a refrigerant circulation loop; The air conditioner also includes a second throttling device, one end of which is used to connect to the pipeline between the condenser (06) and the first throttling device, and the other end of which is used to connect to the suction pipeline of the compressor (01). The first throttling device is an adjustable throttling valve (08); the opening of the first throttling valve (08) has M different levels, and the temperature difference ΔTA between the inlet and outlet of the evaporator (013) has M non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening level of the first throttling valve (08); wherein, the air conditioner also includes a second detection device and a second control device, the second detection device is used to detect the temperature difference ΔTA between the inlet and outlet of the evaporator (013), and the second control device is used to control the opening level of the first throttling valve (08) according to the temperature range where ΔTA is located, so as to increase the opening level of the first throttling valve (08) when ΔTA is in a higher temperature range; The second detection device is used to re-detect the temperature difference ΔTA between the inlet and outlet of the evaporator (013) at time intervals T1; the opening degree of the m-th position of the first throttle valve (08) is Am, where m is a positive integer greater than or equal to 1 and less than or equal to M, and Am is greater than A. m-1 The second control device is also used to adjust the opening degree of the first throttle valve (08) at each position according to the number of times n1 of the detection of the difference ΔTA between the inlet and outlet temperatures of the evaporator (013), so that the opening degree Am of the m-th position of the first throttle valve (08) becomes Am', where Am' = Am + ΔA * n1 * (m-1).

2. The air conditioner according to claim 1, characterized in that: The air conditioner also includes a first detection device and a first control device, wherein the first detection device is used to detect the outdoor ambient temperature where the outdoor unit of the air conditioner is located. The first control device is used to control the opening and closing of the pipeline of the second throttling device according to the outdoor ambient temperature, so as to control the pipeline of the second throttling device to be closed when the outdoor ambient temperature is less than or equal to T, and to control the pipeline of the second throttling device to be opened when the outdoor ambient temperature is greater than T.

3. The air conditioner according to claim 1 or 2, characterized in that: The second throttling device is a second throttling valve (09) with adjustable opening.

4. The air conditioner according to claim 1, characterized in that: The heat exchange fan (012) of the evaporator (013) has M different fan speeds, which correspond one-to-one with each temperature range of ΔTA; The second control device is further configured to control the fan speed of the heat exchange fan (012) of the evaporator (013) according to the temperature range of ΔTA, so as to control the fan speed of the heat exchange fan (012) of the evaporator (013) to be reduced when ΔTA is in a higher temperature range.

5. The air conditioner according to claim 3, characterized in that: The opening degree of the second throttle valve (09) has R different positions. The difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the opening degree of the second throttle valve (09). The air conditioner also includes a third detection device and a third control device. The third detection device is used to detect the difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit. The third control device is used to control the opening level of the second throttle valve (09) according to the temperature range of ΔTB, so as to increase the opening level of the second throttle valve (09) when ΔTB is in a higher temperature range.

6. The air conditioner according to claim 5, characterized in that: The heat exchange fan (05) of the condenser (06) has R different fan speeds, which correspond one-to-one with each temperature range of ΔTB. The third control device is also used to control the fan speed of the heat exchange fan (05) of the condenser (06) according to the temperature range of ΔTB, so as to increase the fan speed of the heat exchange fan (05) of the condenser (06) when ΔTB is in a higher temperature range.

7. The air conditioner according to claim 5 or 6, characterized in that: The third detection device is used to re-detect the difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit at every time interval T2. The opening degree of the r-th position of the second throttle valve (09) is Br, where r is a positive integer greater than or equal to 1 and less than or equal to R, and Br is greater than B. r-1 The third control device is also used to adjust the opening degree of the second throttle valve (09) at each position according to the number of times n2 of the detection of the difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit, so that the opening degree Br of the r-th position of the second throttle valve (09) becomes Br', where Br' = Br - ΔB * n2 * (r-1).

8. The air conditioner according to any one of claims 1, 2, 4-6, characterized in that: The air conditioner also includes a gas-liquid separator (010); The other end of the second throttling device is connected to the suction line of the compressor (01) via the gas-liquid separator (010); and / or, the four-way valve (02) has a first connection end for connecting to the suction line of the compressor (01), the first connection end being connected to the suction line of the compressor (01) via the gas-liquid separator (010).

9. A control method for an air conditioner according to any one of claims 3 to 8, characterized in that: The control method includes the following adjustment steps for the air conditioner: detecting the temperature difference ΔTA between the inlet and outlet of the evaporator (013), and controlling the opening level of the first throttle valve (08) according to the temperature range of ΔTA, so as to increase the opening level of the first throttle valve (08) when ΔTA is in a higher temperature range. And / or, when the second throttling device is an adjustable second throttling valve (09), and the opening of the second throttling valve (09) has R different levels, and the difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and each temperature range corresponds one-to-one with the level of the opening of the second throttling valve (09), the control method includes the following air conditioner adjustment steps: detecting the difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit, and controlling the level of the opening of the second throttling valve (09) according to the temperature range of ΔTB, so as to control the level of the opening of the second throttling valve (09) to decrease when ΔTB is in a higher temperature range.

10. The control method for an air conditioner according to claim 9, characterized in that: When the temperature difference ΔTA between the inlet and outlet of the evaporator (013) has M non-overlapping continuous temperature ranges, and the rotation speed of the heat exchange fan (012) of the evaporator (013) has M different fan speeds that correspond one-to-one with each temperature range of ΔTA, the control method includes the following air conditioner adjustment steps: controlling the fan speed of the heat exchange fan (012) of the evaporator (013) according to the temperature range of ΔTA, so as to control the fan speed of the heat exchange fan (012) of the evaporator (013) to decrease when ΔTA is in a higher temperature range.

11. The control method for an air conditioner according to claim 9 or 10, characterized in that: The opening degree of the m-th position of the first throttle valve (08) is Am, where m is a positive integer greater than or equal to 1 and less than or equal to M, and Am is greater than A. m-1 The control method further includes: The temperature difference ΔTA between the inlet and outlet of the evaporator (013) is rechecked every time interval T1; The opening degree of the first throttle valve (08) at each position is adjusted according to the number of times n1 of the detection of the temperature difference ΔTA between the inlet and outlet of the evaporator (013), so that the opening degree Am of the m-th position of the first throttle valve (08) becomes Am', where Am' = Am + ΔA*n1*(m-1).

12. The control method for an air conditioner according to claim 9, characterized in that: When the temperature difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit has R non-overlapping continuous temperature ranges, and the rotation speed of the heat exchange fan (05) of the condenser (06) has R different fan speeds, which correspond one-to-one with each temperature range of ΔTB, the control method includes the following air conditioner adjustment steps: controlling the fan speed of the heat exchange fan (05) of the condenser (06) according to the temperature range of ΔTB, so as to increase the fan speed of the heat exchange fan (05) of the condenser (06) when ΔTB is in a higher temperature range.

13. The control method for an air conditioner according to claim 9 or 12, characterized in that: The opening degree of the r-th position of the second throttle valve (09) is Br, where r is a positive integer greater than or equal to 1 and less than or equal to R, and Br is greater than B. r-1 The control method further includes: The difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit is re-detected every time T2. The opening degree of the second throttle valve (09) at each position is adjusted according to the number of times n2 of the difference ΔTB between the outlet temperature of the condenser (06) and the ambient temperature of the outdoor unit, so that the opening degree Br of the r-th position of the second throttle valve (09) becomes Br', where Br' = Br - ΔB * n2 * (r-1).

14. The control method for an air conditioner according to claim 9, 10, or 12, characterized in that: Before proceeding with the air conditioner adjustment steps, a test procedure for the air conditioner must be performed first, specifically: The system detects the outdoor ambient temperature of the outdoor unit of the air conditioner. If the outdoor ambient temperature is greater than T, the system enters the air conditioner's adjustment step; otherwise, it controls the closure of the second throttling device's pipeline.

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