CN114777312B - Low temperature refrigeration continuous operation control method, device, air conditioner, storage medium - Google Patents

Abstract

The application provides a low-temperature refrigeration continuous operation control method, a device, an air conditioner and a storage medium, wherein the method comprises the following steps: in the air conditioner low-temperature refrigeration mode, the outdoor fan gear D is adjusted by sequentially dividing the high-pressure Ph of the compressor, the outdoor fan gear D and the compressor pressure ratio gamma by at most three stages, and is based on D=D _{Lower limit of} The first trigger time of Ph < P4 and gamma < gamma 1 is used for executing linkage control on the outdoor fan gear D, the outdoor unit expansion valve and the indoor unit expansion valve; wherein P4 is a fourth preset high voltage value, D _{Lower limit of} The first critical value is used for representing the lower limit of the pressure ratio for the lowest gear and gamma 1 of the outdoor fan. By the low-temperature refrigeration continuous operation control method, the device, the air conditioner and the storage medium, the purpose of continuous and stable operation of the outdoor fan can be realized even when the air conditioner operates in a refrigeration mode at a lower environment temperature.

Description

Low-temperature refrigeration continuous operation control method, device, air conditioner, storage medium

technical field

The present invention relates to the technical field of air conditioning, in particular to a method and device for controlling continuous operation of low-temperature refrigeration, an air conditioner, and a storage medium.

Background technique

At present, when the air conditioner operates in the cooling mode at a relatively low ambient temperature, the outdoor fan will start and stop in a reciprocating manner periodically to ensure the effective operation of the air conditioner in the cooling mode. This is because in low-temperature cooling scenarios, the load demand of the air conditioner is small and the outdoor heat exchanger is too large. When the compressor and the outdoor fan are both adjusted to the minimum operation, the actual cooling capacity will still exceed the load demand, and the outdoor fan can only be stopped. to reduce cooling. However, after the outdoor fan is stopped, the outdoor heat exchanger cannot effectively exchange heat with the surrounding air. As time goes by, the outdoor fan must be turned on to meet the load demand.

As a result, the outdoor fan will start and stop in a reciprocating cycle, which will cause significant fluctuations in the operating temperature and operating noise of the air conditioner, affecting user comfort experience.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is: the first aspect is to propose a low-temperature refrigeration continuous operation control method, so that even when the air conditioner is operating in the cooling mode at a lower ambient temperature, the outdoor fan can continue to run smoothly. Purpose.

In order to solve the above-mentioned technical problem of the first aspect, the present invention proposes a method for controlling continuous operation of low-temperature refrigeration, the method comprising:

In the low-temperature refrigeration mode of the air conditioner, the outdoor fan gear D is adjusted by dividing the high pressure Ph of the compressor, the outdoor fan gear D, and the compressor pressure ratio γ in sequence at most three levels, and based on D=D _{lower limit} , Ph< P4. At the first triggering moment when γ<γ1, the linkage control of the gear position D of the outdoor fan, the expansion valve of the outdoor unit, and the expansion valve of the indoor unit is executed;

Wherein, P4 is the fourth preset high pressure value, _{the lower limit} of D is the lowest gear of the outdoor fan, and γ1 is used to represent the first critical value of the lower limit of the pressure ratio.

Through the low-temperature refrigeration continuous operation control method of the present invention, even when the air conditioner operates in a cooling mode at a relatively low ambient temperature, the purpose of continuous and stable operation of the outdoor fan can be achieved.

Preferably, in the low-temperature refrigeration mode of the air conditioner, the method includes the following specific execution steps:

S1: Timely collection of high pressure Ph;

S2: judging whether Ph>P3 is satisfied, where P3 is the third preset high pressure value greater than P4;

S3: If yes, increase the gear position D of the outdoor fan, and return to step S1; if no, determine whether Ph<P4 is satisfied;

S4: If yes, go to step S5; if not, maintain the gear position D of the outdoor fan, and return to step S1;

S5: According to the trigger judgment of the first trigger moment, downgrade or linkage control the gear position D of the outdoor fan, and return to step S1.

The low-temperature refrigeration mode of this application can ensure the continuous and stable operation of the outdoor fan even when it is operated at a relatively low ambient temperature covering medium and low-temperature refrigeration scenarios, and realize precise control of the gear D of the outdoor fan to avoid compressor damage. reliability risk.

Preferably, step S5 includes the following specific execution steps:

S51: judging whether D>D _{lower limit} is satisfied;

S52: If yes, reduce the gear position D of the outdoor fan, and return to step S1; if no, judge whether γ<γ1 is satisfied;

S53: If yes, the current time meets the first trigger time, go to step S54; if not, the current time does not meet the first trigger time, go to step S55;

S54: Execute the linkage control of the gear position D of the outdoor fan, the expansion valve of the outdoor unit, and the expansion valve of the indoor unit, and return to step S1;

S55: The indoor and outdoor expansion valves maintain the conventional throttling adjustment mode, and return to step S1.

Steps S1-S5 are a set of closed-loop cycle control, and steps S51-S55 are set in detail: according to the trigger judgment of the first trigger moment, the specific sub-cycle control of downgrading or linkage control of the gear position D of the outdoor fan is set to Accurately determine the first trigger moment, and ensure the smooth implementation of the entire closed-loop control.

Preferably, step S55 includes the following specific operational steps:

S551: Judging whether γ>γ2 is satisfied, wherein γ2 is used to represent the second critical value of the lower limit of the pressure ratio, and γ2>γ1;

S552: If yes, the indoor and outdoor expansion valves maintain the conventional throttling adjustment mode, and return to step S1; if not, execute step S553;

S553: Keep the current adjustment mode of the indoor and outdoor expansion valve unchanged, and return to step S1.

It is beneficial to keep a certain margin for the reliability control of the compressor, so as to avoid the pressure ratio from entering the small range; especially, the setting of step S553 can be used to make the throttling adjustment of the indoor and outdoor expansion valves within a certain inertia Follow the previous original adjustment method within the range to expand the alternate operating range applicable to the two throttling adjustment methods, thereby reducing the impact on other state parameters of the system.

Preferably, step S54 includes the following steps:

S541: The opening of the outdoor electronic expansion valve is closed ΔEVO=η1*γ1, and the opening of the indoor electronic expansion valve is increased ΔEVI=η2*γ1, where η1 and η2 are coefficients;

S542: Return to step S1.

The pressure ratio γ can be rapidly increased away from the first critical value of γ1.

Preferably, the cooling mode of the air conditioner includes at least two types of low-temperature cooling mode and high-temperature cooling mode, and the method includes the following identifying operation steps:

S05: Collect outdoor ambient temperature Ta in real time or regularly;

S06: judging whether Ta<Ta2 is satisfied, wherein Ta2 is the second preset temperature;

S07: If yes, execute step S09; if not, judge whether Ta>Ta1 is satisfied, wherein Ta1 is the first preset temperature higher than Ta2;

S08: If yes, execute step S010; if not, execute step S011;

S09: Run the low-temperature refrigeration mode, and return to step S05;

S010: Run the high-temperature refrigeration mode, and return to step S05;

S011: Keep the current cooling mode unchanged, and return to step S05.

It is beneficial to ensure the stability of the air-conditioning system to a large extent, and at the same time, the low-temperature cooling mode can also be extended to apply to medium and low-temperature cooling scenarios. Similarly, the high-temperature cooling mode can also be expanded to apply to medium- and high-temperature cooling scenarios.

Preferably, the high-temperature cooling mode only adjusts the gear position D of the outdoor fan based on the primary determination of the high pressure Ph.

The high-temperature cooling mode only adjusts the gear position D of the outdoor fan based on the first-level determination of the high pressure Ph, which can easily achieve precise control of the gear position D of the outdoor fan, and prevents the compressor from generating a second noise caused by the high pressure Ph being too high. reliability risk.

The technical problem to be solved by the present invention is that: the second aspect provides a low-temperature refrigeration continuous operation control device, and/or the third aspect provides an air conditioner, and/or the fourth aspect provides a computer-readable storage medium, This enables the air conditioner to achieve the purpose of continuous and stable operation of the outdoor fan even when the air conditioner operates in a cooling mode at a relatively low ambient temperature.

In order to solve the above-mentioned technical problem of the second aspect, the present invention provides a low-temperature refrigeration continuous operation control device for performing the method described in any embodiment of the first aspect, the device comprising:

The first judgment and adjustment module: used to adjust the gear position D of the outdoor fan by sequentially dividing the high pressure Ph of the compressor, the gear position D of the outdoor fan, and the pressure ratio γ of the compressor to three levels in sequence;

The second judgment and adjustment module: used to execute the adjustment of the gear _position D of the outdoor fan, outdoor fan gear D, and The linkage control of the expansion valve of the indoor unit and the expansion valve of the indoor unit; among them, P4 is the fourth preset high pressure value, _{the lower limit} of D is the lowest gear of the outdoor fan, and γ1 is used to represent the first critical value of the lower limit of the pressure ratio.

In order to solve the technical problem of the third aspect above, the present invention provides an air conditioner, including a computer-readable storage medium storing a computer program and a processor, and when the computer program is read and run by the processor, the first In one aspect, the method described in any one of the embodiments.

In order to solve the technical problem of the fourth aspect above, the present invention provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the first aspect is realized. The method described in any embodiment.

Compared with the prior art, the low-temperature refrigeration continuous operation control method, device, air conditioner, and computer storage medium of the present invention have the following beneficial effects:

1) Even when the air conditioner is running in cooling mode at a lower ambient temperature, the outdoor fan can continue to run smoothly, and at the same time avoid the system refrigerant noise caused by the frequent start and stop of the outdoor fan;

2) Significantly reduce the fluctuations of the operating temperature and operating noise of the air conditioner in the low-temperature refrigeration scene, and improve the user's comfort experience;

3) For the cooling scene under any Ta value, through the identification of the outdoor ambient temperature, the different target control of the outdoor fan gear at lower ambient temperature and higher ambient temperature is realized, and the outdoor fan gear control is more accurate.

Description of drawings

The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is a schematic plan view of an outdoor unit of an air conditioner described in Embodiment 1 of the present invention.

Detailed ways

In order to make the above objectives, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described in the present invention are only part of the embodiments of the present invention, which are only used to explain the present invention and do not constitute a limitation to the present invention. The embodiments and the features in the embodiments can be combined with each other.

Example 1

Referring to Fig. 1, the present invention proposes a method for controlling continuous operation of low-temperature refrigeration, the method comprising:

In the low-temperature refrigeration mode of the air conditioner, the outdoor fan gear D is adjusted by dividing the high pressure Ph of the compressor, the outdoor fan gear D, and the compressor pressure ratio γ in sequence at most three levels, and based on D=D _{lower limit} , Ph< P4. At the first triggering moment when γ<γ1, the linkage control of the gear position D of the outdoor fan, the expansion valve of the outdoor unit, and the expansion valve of the indoor unit is executed;

Wherein, P4 is the fourth preset high pressure value, _{the lower limit} of D is the lowest gear of the outdoor fan, and γ1 is used to represent the first critical value of the lower limit of the pressure ratio.

Specifically, when the air conditioner operates in the cooling mode at a lower ambient temperature, the high pressure Ph will continue to drop during the process of reducing the compressor and the outdoor fan to the minimum operation, resulting in a decrease in the pressure ratio γ and the risk of compressor wear. increase. Furthermore, when the actual cooling capacity still exceeds the load demand, in the prior art, the cooling of the air conditioner can only be reduced by intermittently stopping the outdoor fan and avoiding the continuous decrease of the high pressure Ph.

However, in the present invention, the air conditioner can be set with a low-temperature cooling mode. In this low-temperature cooling mode, the outdoor fan gear D can be precisely divided into three stages at most by the high pressure Ph, the outdoor fan gear D, and the compressor pressure ratio γ. adjustment, in an effort to maintain the dynamic balance between compressor frequency reduction, outdoor fan gear reduction, and compressor reliability guarantee in low-temperature refrigeration scenarios, and when it is accurately identified that the above dynamic balance is about to end with "pressure ratio γ is too low At the first triggering moment when the mode of " is dynamically broken, the linkage control of outdoor fan gear D, outdoor unit expansion valve, and indoor unit expansion valve is executed to increase the pressure ratio γ away from the first critical value of γ1, so as to continue to maintain compression The machine is within the preset reliability range. Subsequently, the gear position D of the outdoor fan can at least continue to run in the manner of D=D _{lower limit} to avoid shutdown, thereby effectively replacing the processing method of "intermittently stopping the outdoor fan" in the prior art, so that the air conditioner even When the cooling mode is operated at a lower ambient temperature, the purpose of continuous and stable operation of the outdoor fan can also be achieved.

Preferably, the cooling mode of the air conditioner includes at least two types of low-temperature cooling mode and high-temperature cooling mode, and the method includes the following identifying operation steps:

S05: Collect outdoor ambient temperature Ta in real time or regularly;

S06: judging whether Ta<Ta2 is satisfied, wherein Ta2 is the second preset temperature;

S07: If yes, execute step S09; if not, judge whether Ta>Ta1 is satisfied, wherein Ta1 is the first preset temperature higher than Ta2;

S08: If yes, execute step S010; if not, execute step S011;

S09: Run the low-temperature refrigeration mode, and return to step S05;

S010: Run the high-temperature refrigeration mode, and return to step S05;

S011: Keep the current cooling mode unchanged, and return to step S05.

Specifically, the cooling mode of the air conditioner may only include a low-temperature cooling mode and a high-temperature cooling mode. During the operation of the air-conditioning cooling mode, the corresponding cooling mode may be selected for operation according to the effective identification of the outdoor ambient temperature Ta. Wherein, when the judgment result of step S08 is negative, that is, corresponding to Ta2≤Ta≤Ta1, since both Ta2 and Ta1 are preset critical temperature values, when the outdoor ambient temperature Ta is near any one of Ta2 and Ta1, a high frequency When the fluctuation is low, the setting of step S011 can effectively avoid the frequent switching of the cooling mode of the air conditioner. It is beneficial to ensure the operation stability of the air conditioning system to a large extent. At the same time, given that Ta2≤Ta≤Ta1 actually corresponds to medium-temperature cooling scenarios, the low-temperature cooling mode can actually be extended to medium-low temperature cooling scenarios, and the high-temperature cooling mode can also be expanded to medium-high temperature cooling scenarios. Of course, unless the outdoor ambient temperature Ta has a sufficiently large change, there may be a jump between the low-temperature cooling mode and the high-temperature cooling mode, thereby ensuring that the automatic switching of the air-conditioning cooling mode is actually adapted to extreme weather conditions.

As one of the preferred examples of the present invention, Ta2∈[15°C, 20°C], Ta1∈[25°C, 28°C]. Referring to the national standard, 18°C is the minimum cooling demand. When the outdoor ambient temperature Ta is lower than this value, the cooling load demand will tend to decrease significantly. In this invention, Ta2∈[15°C, 20°C] is set to correspond to low-temperature refrigeration The upper limit temperature of the scene. Similarly, according to the reference value of the comfortable temperature experienced by the human body in the range of 25°C to 28°C, when the outdoor ambient temperature Ta is greater than this value, the cooling load demand will tend to increase significantly, and Ta1∈[25°C is set in the present invention , 28°C] to correspond to the lower limit temperature of the high-temperature cooling scene. For the interval transition value corresponding to Ta2≤Ta≤Ta1, at least a span of 5°C can already guarantee the operation stability of the air conditioning system to a large extent; while a span of at most 13°C will greatly expand the low-temperature refrigeration mode and expand its application to The scope of application of medium and low temperature refrigeration scenarios, and/or the high temperature refrigeration mode has also been greatly expanded to expand the scope of application of medium and high temperature refrigeration scenarios. Specifically, optimization settings can be performed according to actual needs.

Preferably, the cooling mode of the air conditioner also includes a normal cooling mode, and before step S05, the method further includes the following identifying operation steps:

S01: Start the air conditioner cooling mode;

S02: Determine whether Ta2≤Ta'≤Ta1 is satisfied, where Ta' is the outdoor ambient temperature at the moment when the air-conditioning cooling mode is started;

S03: If yes, run the conventional refrigeration mode, and go to step S05; if not, judge whether Ta<Ta2 is satisfied;

S04: If yes, execute step S09; if not, execute step S010.

Specifically, when Ta2≦Ta′≦Ta1, the air conditioner may choose to start and run only in the normal cooling mode. Furthermore, during the subsequent operation of the air conditioner, as long as the temperature fluctuation of the outdoor ambient temperature Ta jumps out of the medium-temperature cooling scenario of Ta2≤Ta≤Ta1, the cooling mode of the air conditioner will switch to one of the low-temperature cooling mode or the high-temperature cooling mode, It is not allowed to return to the normal cooling mode; otherwise, during the subsequent operation of the air conditioner, the air conditioner only needs to keep running in the normal cooling mode.

Therefore, for any cooling scenario with any Ta value, when the fluctuation range of the outdoor ambient temperature Ta has not jumped out of the medium-temperature cooling scenario of Ta2≤Ta≤Ta1, the air conditioner only needs to adopt the conventional cooling mode to ensure that the outdoor fan continues to operate. Accurate gear control under stable operation; on the contrary, the air conditioner can adopt a more reasonable low-temperature cooling mode and/or high-temperature cooling mode, that is, through different target controls at medium-low ambient temperature and medium-high ambient temperature, to ensure that the outdoor fan Precise gear control for continuous smooth operation.

Preferably, in the low-temperature refrigeration mode of the air conditioner, the method includes the following specific execution steps:

S1: Timely collection of high pressure Ph;

S2: judging whether Ph>P3 is satisfied, where P3 is the third preset high pressure value greater than P4;

S3: If yes, increase the gear position D of the outdoor fan, and return to step S1; if no, determine whether Ph<P4 is satisfied;

S4: If yes, go to step S5; if not, maintain the gear position D of the outdoor fan, and return to step S1;

S5: According to the trigger judgment of the first trigger moment, downgrade or linkage control the gear position D of the outdoor fan, and return to step S1.

Specifically, as mentioned above, the low-temperature cooling mode is not only applicable to low-temperature cooling scenarios where Ta<Ta2, but also can be extended to apply to medium-low temperature cooling scenarios where Ta≤Ta1. In the medium and low temperature cooling scenario, the outdoor fan gear D will generate corresponding increase, maintenance, and decrease demands, so that the precise adjustment of the outdoor fan gear D will always match the cooling load fluctuation of the air conditioning system in the medium and low temperature cooling scenario . Although the present invention adjusts the gear position D of the outdoor fan by "sequentially dividing the high pressure Ph of the compressor, the gear position D of the outdoor fan, and the pressure ratio of the compressor γ at most", it only needs to pass the first step of the high pressure Ph One-level division can accurately determine the need for precise adjustment of the speed of the outdoor fan. For example:

In the present invention, P4∈[11bar, 13bar] can be set, and its corresponding refrigerant saturation temperature is 10°C to 15°C, which is about 5°C lower than Ta2∈[15°C, 20°C]. User set temperature is equivalent. When the high pressure Ph is less than P4, the cooling load demand of the system tends to decrease significantly, which can basically be regarded as no cooling load demand, and there is basically no need for heat exchange temperature difference, and the speed demand of the outdoor fan is correspondingly reduced significantly. Gear D is downshifted.

Similarly, P3∈[14bar, 16bar] can be set in the present invention, and its corresponding refrigerant saturation temperature is about 20°C-25°C, which is about 5°C higher than Ta2∈[15°C, 20°C]. Considering that in the medium and low temperature refrigeration scenario, the speed of the outdoor fan has a significant impact on the high pressure Ph, taking Ta2 as a reference, the system heat transfer temperature difference only needs to be maintained at about 5°C. When the high pressure Ph is greater than P3, the cooling load demand of the system will tend to increase significantly. At this time, the heat transfer temperature difference of the system should also increase significantly, and the corresponding outdoor fan speed needs to increase significantly. It is necessary to increase the gear D of the outdoor fan. file processing.

Furthermore, when P4≤Ph≤P3, the cooling load fluctuation range of the system is moderate, and the gear position D of the outdoor fan only needs to be maintained. At the same time, in view of the medium and low temperature cooling scenarios corresponding to the low-temperature cooling mode, the gear D of the outdoor fan usually has a large room for upshifting. Therefore, if the result in step S3 is Yes, the gear D of the outdoor fan can be directly upshifted. On the contrary, when the result in step S4 is yes, it can only be determined that the speed requirement of the outdoor fan has decreased significantly, but the gear D of the outdoor fan cannot be downshifted directly. Because the gear D of the outdoor fan may already be at the lowest gear of the lower _limit of D, that is, there will be a problem that there is no way to lower it under the premise of ensuring the continuous and stable operation of the outdoor fan. Trigger judgment, downgrade or linkage control outdoor fan gear D. Therefore, the low-temperature refrigeration mode of the present application can ensure the continuous and stable operation of the outdoor fan even if it operates at a relatively low ambient temperature covering medium and low-temperature refrigeration scenarios, and realize precise control of the gear D of the outdoor fan, avoiding Compressors create reliability risks.

Preferably, step S5 includes the following specific execution steps:

S51: judging whether D>D _{lower limit} is satisfied;

S52: If yes, reduce the gear position D of the outdoor fan, and return to step S1; if no, judge whether γ<γ1 is satisfied;

S53: If yes, the current time meets the first trigger time, go to step S54; if not, the current time does not meet the first trigger time, go to step S55;

S54: Execute the linkage control of the gear position D of the outdoor fan, the expansion valve of the outdoor unit, and the expansion valve of the indoor unit, and return to step S1;

S55: The indoor and outdoor expansion valves maintain the conventional throttling adjustment mode, and return to step S1.

Specifically, steps S1-S5 are a set of closed-loop control. Assuming that the gear position D of the outdoor fan is only slightly higher than _{the lower limit of} D in step S51, it will return to step S1 immediately after being reduced by one gear in step S52. Enter the next round of cyclic control by choosing an opportunity, that is, this round of cyclic control will only correspond to: the high pressure Ph of the compressor and the gear D of the outdoor fan are divided in two stages to lower the gear D of the outdoor fan. As the gear D of the outdoor fan is reduced by one gear, the effective heat exchange capacity of the outdoor heat exchanger decreases, and the high pressure Ph will most likely increase. In the next round of loop control process, when the three-level division judgments of Ph<P4, D=D _{lower limit} , and γ<γ1 are sequentially satisfied, the current moment will meet the first trigger moment, and then step S54 will be executed. The linkage control of the gear position D of the outdoor fan, the expansion valve of the outdoor unit, and the expansion valve of the indoor unit in order to increase the pressure ratio γ away from the first critical value of γ1; A conventional throttling adjustment mode (hereinafter referred to as the first throttling adjustment mode) under coordinated control with the frequency of the compressor is sufficient.

Preferably, step S55 includes the following specific operational steps:

S551: Judging whether γ>γ2 is satisfied, wherein γ2 is used to represent the second critical value of the lower limit of the pressure ratio, and γ2>γ1;

S552: If yes, the indoor and outdoor expansion valves maintain the conventional throttling adjustment mode, and return to step S1; if not, execute step S553;

S553: Keep the current adjustment mode of the indoor and outdoor expansion valve unchanged, and return to step S1.

Specifically, the linkage control of the gear position D of the outdoor fan, the expansion valve of the outdoor unit, and the expansion valve of the indoor unit in step S54 can be referred to as the second throttling adjustment mode for indoor and outdoor expansion valves. The purpose of the first threshold value being farther from γ1 than γ is that it may not be very throttled compared to the first throttling adjustment mode. Since the steps S1-S5 are a set of closed-loop control, the first throttling adjustment mode and the second throttling adjustment mode may be operated alternately, so as to achieve different predetermined goals. Therefore, when step S55 is subdivided into steps S551-S553 that introduce γ2, it is beneficial to reserve a certain margin for the reliability control of the compressor, thereby avoiding the pressure ratio from entering the small range; Setting, so that the throttling adjustment of the indoor and outdoor expansion valves can follow the previous original adjustment method within a certain inertia range, so as to expand the alternate operating range applicable to the two throttling adjustment methods, thereby reducing the impact on other states of the system. influence of parameters.

As one of the preferred examples of the present invention, γ1∈[2.5, 3], γ2∈[3.5, 4]. Among them, the compressor specifications usually require a minimum pressure ratio of 2 to 2.5, so setting γ1∈[2.5, 3] in the present invention can prevent the pressure ratio from entering the small area to wear the compressor; and for The setting of γ2∈[3.5, 4] can further reserve a certain margin for the reliability control of the compressor to reduce the impact on other state parameters of the system. For example:

In the third-level judgment process for γ, when the judgment result is γ>γ2, the pressure ratio γ is higher, and the indoor and outdoor expansion valves do not need to make any changes with the second throttling adjustment method at all; and when the judgment result is When γ1≤γ≤γ2, the pressure ratio γ is in the controllable range, and it is only necessary to keep the current adjustment method unchanged according to step S553.

Preferably, step S54 includes the following steps:

S541: The opening of the outdoor electronic expansion valve is closed ΔEVO=η1*γ1, and the opening of the indoor electronic expansion valve is increased ΔEVI=η2*γ1, where η1 and η2 are coefficients;

S542: Return to step S1.

Specifically, the opening of the outdoor electronic expansion valve is small to increase the high pressure Ph, while the opening of the indoor electronic expansion valve is large to reduce the low pressure Ps. Since the pressure ratio γ=Ph/Ps, the pressure ratio γ can be rapidly increased away from The first critical value of γ1. Among them, the sampling positions of the high pressure Ph and the low pressure Ps can be seen in Figure 1, ΔEVO and/or ΔEVI can be adjusted according to the pressure ratio change, and the coefficients η1 and/or η2 can be selected according to the experimental experience, generally 1～ between 5.

Preferably, the high-temperature cooling mode only adjusts the gear position D of the outdoor fan based on the primary determination of the high pressure Ph.

Specifically, the reliability risk of the compressor mainly comes from two aspects. The first aspect is as mentioned above: if the pressure ratio γ is too low, the compressor will wear out; the second aspect is that the high pressure Ph is too high, which exceeds the system high pressure. limit, and also wears out the compressor. As mentioned in the background technology, when the air conditioner operates in the cooling mode at a lower ambient temperature, the outdoor fan will start and stop periodically, which prevents the high pressure Ph from falling again as time goes by after the outdoor fan stops. Continue to rise to an excessively high level, which brings the second aspect of compressor reliability risk.

In the present invention, through the operation setting of the low-temperature refrigeration mode, at least in the medium-low temperature refrigeration scene, the continuous and stable operation of the outdoor fan is ensured, and the reliability risk of the compressor in the above two aspects is effectively avoided. In the medium-high temperature cooling scenario corresponding to the high-temperature cooling mode, the compressor does not have the first reliability risk from the low pressure ratio γ, so the high-temperature cooling mode only adjusts the outdoor temperature based on the primary judgment of the high pressure Ph. The fan gear D can easily realize precise control of the outdoor fan gear D, and avoid the second reliability risk of the compressor from the high pressure Ph being too high.

As one of the preferred implementations of the present invention, in the high-temperature refrigeration mode of the air conditioner, the method includes the following specific execution steps:

S1': regularly collect high pressure Ph;

S2': judging whether Ph>P1 is satisfied, where P1 is the first preset high pressure value;

S3': If yes, increase the gear position D of the outdoor fan, and return to step S1'; if no, judge whether Ph<P2 is satisfied, where P2 is the second preset high pressure value smaller than P1;

S4': If yes, reduce the outdoor fan gear D, and return to step S1'; if not, maintain the outdoor fan gear D, and return to step S1'.

Specifically, as mentioned above, the high-temperature cooling mode is not only applicable to the high-temperature cooling scene of Ta>Ta1, but also can be expanded to be applicable to the medium-high temperature cooling scene of Ta≥Ta2. In the medium-high temperature cooling scenario, the outdoor fan gear D will generate corresponding increase, maintenance, and decrease demands, so that the precise adjustment of the outdoor fan gear D will always match the cooling load fluctuation of the air conditioning system in the medium-high temperature cooling scenario . In the high-temperature cooling mode, the precise control of the outdoor fan gear D can be easily achieved through the target control of the high-pressure pressure Ph, and the reliability risk of the high-pressure Ph of the compressor being too high can be avoided. For example:

In the present invention, P1∈[21bar, 23bar] can be set, and the corresponding refrigerant saturation temperature is 35°C-38°C, which is about 10°C higher than the comfortable temperature Ta1∈[25°C, 28°C] experienced by the human body. Considering that in the medium-high temperature cooling scenario, the influence of the speed of the outdoor fan on the high-pressure pressure Ph is not too obvious compared with that in the medium-low temperature cooling scenario, taking Ta1 as a reference, the system heat exchange temperature difference needs to be maintained at about 10°C. When the high pressure Ph is greater than P1, the cooling load demand of the system will tend to increase significantly. At this time, the heat exchange temperature difference of the system should also increase significantly, and the corresponding speed requirement of the outdoor fan will increase significantly. It is necessary to increase the gear D of the outdoor fan. file processing.

Similarly, in the present invention, P2∈[16bar, 18bar] can be set, and the corresponding refrigerant saturation temperature is 25°C-28°C, which is equivalent to the comfortable temperature Ta1∈[25°C, 28°C] experienced by the human body, that is, it is basically It is equivalent to the user-set temperature in high-temperature cooling scenarios. When the high pressure Ph is less than P2, the cooling load demand of the system will tend to decrease significantly, which can basically be regarded as no cooling load demand, and there is basically no need for heat exchange temperature difference, and the speed demand of the outdoor fan will decrease significantly accordingly. Gear D is downshifted.

Furthermore, when P2≤Ph≤P1, the fluctuation range of the cooling load of the system is moderate, and the gear position D of the outdoor fan only needs to be maintained. Similarly, steps S1'-S4' are also a set of closed-loop control, which is much simpler in logic than the closed-loop control of steps S1-S5, and will not be repeated here. See steps S01-S011 at the same time. The two sets of closed-loop loop controls can also automatically jump and switch when certain conditions are met, and they will not be repeated here.

What needs to be explained here is that when the air conditioning system is designed, there is usually a large operating room for the outdoor fan gear D, that is, in the medium-high temperature cooling scenario corresponding to the high-temperature cooling mode, when the outdoor fan gear D When D has increased to the upper _limit of the highest gear D of the outdoor fan, the high pressure Ph will also drop significantly. Then, the second reliability risk of the compressor from the high high pressure Ph can also be basically ruled out.

Therefore, the high-temperature cooling mode of the present application can easily realize the precise control of the gear D of the outdoor fan and avoid the high-pressure Ph Excessive reliability risk.

Example 2

Referring to Figure 1, the present invention also provides a low-temperature refrigeration continuous operation control device for performing the method described in Embodiment 1, the device comprising:

The first judgment and adjustment module: used to adjust the gear position D of the outdoor fan by sequentially dividing the high pressure Ph of the compressor, the gear position D of the outdoor fan, and the pressure ratio γ of the compressor to three levels in sequence;

The second judgment and adjustment module: used to execute the adjustment of the gear _position D of the outdoor fan, outdoor fan gear D, and The linkage control of the expansion valve of the indoor unit and the expansion valve of the indoor unit; among them, P4 is the fourth preset high pressure value, _{the lower limit} of D is the lowest gear of the outdoor fan, and γ1 is used to represent the first critical value of the lower limit of the pressure ratio.

The present invention also provides an air conditioner, including a computer-readable storage medium and a processor storing a computer program, and when the computer program is read and run by the processor, the method as described in Embodiment 1 is implemented .

The present invention also provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, the method as described in Embodiment 1 is implemented.

Specifically, those skilled in the art can understand that the low-temperature refrigeration continuous operation control device, air conditioner, and computer-readable storage medium provided in Embodiment 2 can all be implemented by combining software and hardware. The method described in 1. For any one of the above-mentioned low-temperature refrigeration continuous operation control device, air conditioner, and computer-readable storage medium, its information interaction, execution process, etc. can refer to the description of the low-temperature refrigeration continuous operation control method in Embodiment 1, and will not be repeated here. Let me repeat them one by one.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (7)

1. A method for controlling continuous operation of low temperature refrigeration, the method comprising:

in the air conditioner low-temperature refrigeration mode, the outdoor fan gear D is adjusted by sequentially dividing the high-pressure Ph of the compressor, the outdoor fan gear D and the compressor pressure ratio gamma by at most three stages, and is based on D=D _{Lower limit of} The first trigger time of Ph < P4 and gamma < gamma 1 is used for executing linkage control on the outdoor fan gear D, the outdoor unit expansion valve and the indoor unit expansion valve;

wherein P4 is a fourth preset high voltage value, D _{Lower limit of} The first critical value is the lowest gear and gamma 1 of the outdoor fan and used for representing the lower limit of the pressure ratio;

the specific implementation steps are as follows:

s1: the method comprises the steps of (1) regularly collecting high-pressure Ph;

s2: judging whether Ph > P3 is met, wherein P3 is a third preset high-voltage value larger than P4;

s3: if yes, the gear D of the outdoor fan is increased, and the step S1 is returned; if not, judging whether Ph is less than P4;

s4: if yes, executing step S5; if not, maintaining the gear D of the outdoor fan, and returning to the step S1;

s5: according to the triggering judgment of the first triggering moment, the gear D of the outdoor fan is regulated down or controlled in a linkage mode, and the step S1 is returned;

step S5 further includes the following specific implementation steps:

s51: judging that D is more than D _{Lower limit of} Whether or not it is satisfied;

s52: if yes, the gear D of the outdoor fan is reduced, and the step S1 is returned; if not, judging whether gamma is less than gamma 1;

s53: if yes, the current moment satisfies the first trigger moment, and step S54 is executed; if not, the current moment does not meet the first trigger moment, and the step S55 is executed;

s54: executing linkage control on the gear D of the outdoor fan, the expansion valve of the outdoor unit and the expansion valve of the indoor unit, and returning to the step S1;

s55: the indoor and outdoor expansion valves maintain a conventional throttling adjustment mode, and return to the step S1;

step S54 further includes the following specific implementation steps:

s541: the opening degree of the outdoor electronic expansion valve is reduced by delta EVO=eta 1 by gamma 1, and the opening degree of the indoor electronic expansion valve is increased by delta EVI=eta 2 by gamma 1, wherein eta 1 and eta 2 are coefficients;

s542: returning to step S1.

2. The method of claim 1, wherein step S55 includes the following steps:

s551: judging whether gamma is more than gamma 2 or not, wherein gamma 2 is used for representing a second critical value of the lower limit of the pressure ratio, and gamma 2 is more than gamma 1;

s552: if yes, maintaining a conventional throttling adjustment mode by the indoor and outdoor expansion valves, and returning to the step S1; if not, go to step S553;

s553: the indoor and outdoor expansion valves maintain the current adjusting mode unchanged, and return to the step S1.

3. The method according to claim 1 or 2, wherein the air-conditioning cooling mode includes at least two of a low-temperature cooling mode and a high-temperature cooling mode, the method further comprising the step of identifying operation as follows:

s05: collecting outdoor environment temperature Ta in real time or at regular time;

s06: judging whether Ta is smaller than Ta2 or not, wherein Ta2 is a second preset temperature;

s07: if yes, go to step S09; if not, judging whether Ta is more than Ta1, wherein Ta1 is a first preset temperature higher than Ta 2;

s08: if yes, executing step S010; if not, executing step S011;

s09: operating the low-temperature refrigeration mode, and returning to the step S05;

s010: operating the high-temperature refrigeration mode and returning to the step S05;

s011: the current cooling mode is maintained unchanged and the process returns to step S05.

4. A cryogenically continuous operation control method according to claim 3 wherein the high temperature refrigeration mode adjusts the outdoor fan gear D based on only one level of determination of the high pressure Ph.

5. A cryogenically sustained-operation control apparatus for performing the method as recited in any one of claims 1 to 4, the apparatus comprising:

the first judgment and adjustment module: the method is used for adjusting the outdoor fan gear D by dividing the high pressure Ph of the compressor, the outdoor fan gear D and the compressor pressure ratio gamma into at most three stages in sequence in the low-temperature refrigeration mode of the air conditioner;

and a second judgment and adjustment module: for in the judgment adjustment process of the first judgment adjustment module, based on d=d _{Lower limit of} The first trigger time of Ph < P4 and gamma < gamma 1 is used for executing linkage control on the outdoor fan gear D, the outdoor unit expansion valve and the indoor unit expansion valve; wherein P4 is a fourth preset high voltage value, D _{Lower limit of} The first critical value is used for representing the lower limit of the pressure ratio for the lowest gear and gamma 1 of the outdoor fan.

6. An air conditioner comprising a computer readable storage medium storing a computer program and a processor, the computer program implementing the method of any one of claims 1-4 when read and run by the processor.

7. A computer readable storage medium, characterized in that the computer readable storage medium stores a computer program which, when read and run by a processor, implements the method according to any of claims 1-4.