Air conditioner

Abstract

The invention discloses an air conditioner, and relates to the technical field of air conditioner control. The air conditioner comprises an indoor heat exchanger, an outdoor heat exchanger, a compressor, a refrigerant temperature sensor and a controller. The compressor, the indoor heat exchanger and the outdoor heat exchanger jointly form a refrigerant circulation loop, and a refrigerant flows in the refrigerant circulation loop. The refrigerant temperature sensor is arranged in the refrigerant circulation loop and used for detecting the temperature of a refrigerant; the controller is connected with the compressor and the refrigerant temperature sensor. The controller is configured to regularly obtain a temperature value of a refrigerant, and when the temperature value of the refrigerant is larger than a first preset value, the compressor is controlled to stop running; when the temperature value of the refrigerant is smaller than or equal to a first preset value, the temperature change trend of the refrigerant is further judged according to the obtained temperature value of the refrigerant; if the temperature of the refrigerant changes in the rising trend, when the temperature value of the refrigerant is larger than a second preset value, the frequency of the compressor is controlled to be reduced; when the temperature value of the refrigerant is larger than the third preset value and smaller than or equal to the second preset value, the frequency of the compressor is forbidden to increase; when the temperature value of the refrigerant is smaller than or equal to a third preset value, the compressor frequency is adjusted according to the current operation working condition of the air conditioner; and if the temperature of the refrigerant changes in the decreasing trend, the frequency of the compressor is forbidden from increasing.

Description

Technical Field

[0001] This application relates to the technical field of air conditioning control, and more particularly to an air conditioner. Background Technology

[0002] When a variable frequency air conditioner is running, the compressor's operating frequency is usually adjusted according to the refrigerant pressure in the system. If the frequency decreases too slowly, the system pressure may continue to rise, damaging the compressor. If the frequency decreases too quickly, the system pressure may fluctuate, causing the entire system to become unstable, resulting in a poor user experience or even damaging the air conditioning system.

[0003] Currently, air conditioning systems typically include pressure sensors and / or temperature sensors. The pressure sensor detects the refrigerant pressure, while the temperature sensor detects the refrigerant temperature. The controller monitors the system's operating status based on the information from these sensors. In case of potential malfunction, the controller promptly adjusts the compressor frequency to protect the system.

[0004] In some inverter air conditioners, the air conditioning system is only equipped with a temperature sensor. Since the temperature sensor's detection information usually lags behind the refrigerant's state, adjusting the compressor frequency based on the temperature sensor's detection information can easily lead to compressor frequency fluctuations, causing system control instability. It can also easily cause the compressor to stop frequently, affecting user experience and the lifespan of the air conditioner. Summary of the Invention

[0005] To address the shortcomings of related technologies, this application provides an air conditioner that formulates multiple protection strategies based on the severity of adverse consequences arising from abnormal operation of the air conditioning system; it determines whether the air conditioning system needs protection and which protection strategy to implement based on the refrigerant temperature value and the refrigerant temperature change trend, thereby ensuring the stability and reliability of the air conditioning system operation.

[0006] This application provides an air conditioner, including:

[0007] Indoor heat exchanger, used for exchanging heat with indoor air;

[0008] An outdoor heat exchanger is used to exchange heat with outdoor air.

[0009] The compressor, together with the indoor heat exchanger and the outdoor heat exchanger, forms a refrigerant circulation loop. Refrigerant flows in the refrigerant circulation loop. The compressor is used to compress low-pressure refrigerant gas into high-pressure refrigerant gas and drive the refrigerant to flow in the refrigerant circulation loop.

[0010] A refrigerant temperature sensor is installed in the refrigerant circulation loop to detect the temperature of the refrigerant.

[0011] The controller is connected to the compressor and refrigerant temperature sensor respectively; the controller is configured as follows:

[0012] The temperature of the refrigerant is periodically measured, and when the temperature of the refrigerant exceeds the first preset value, the compressor is controlled to stop running.

[0013] When the temperature value of the refrigerant is less than or equal to the first preset value, the temperature change trend of the refrigerant is further judged based on the obtained temperature value of the refrigerant.

[0014] If the refrigerant temperature shows an upward trend, when the refrigerant temperature is greater than the second preset value, the compressor frequency is controlled to decrease; when the refrigerant temperature is less than or equal to the second preset value but greater than the third preset value, the compressor frequency is prohibited from increasing; when the refrigerant temperature is less than or equal to the third preset value, the compressor frequency is adjusted according to the current operating conditions of the air conditioner.

[0015] If the refrigerant temperature shows a downward trend, the compressor frequency should not be increased.

[0016] This technical solution compares the acquired refrigerant temperature value with a first preset value, a second preset value, and a third preset value, and combines this with the refrigerant temperature change trend to adjust the compressor frequency, thereby protecting the air conditioning system and ensuring the stability and reliability of its operation.

[0017] In some embodiments, the controller is further configured to restart the compressor when the temperature of the refrigerant is less than or equal to a third preset value after the compressor stops running.

[0018] In some embodiments, the controller is further configured to: when the temperature of the refrigerant changes in a downward trend, if the temperature value of the refrigerant is greater than a third preset value, then prohibit the compressor frequency from increasing; if the temperature value of the refrigerant is less than or equal to the third preset value, then adjust the compressor frequency according to the current operating conditions of the air conditioner.

[0019] In some embodiments, the controller is further configured to: when the compressor frequency is prohibited from increasing, if the current compressor frequency is lower than or equal to the compressor's target frequency under the current operating conditions of the air conditioner, control the compressor to maintain its current frequency; if the current compressor frequency is higher than the target frequency, adjust the compressor frequency according to the target frequency.

[0020] In some embodiments, the controller is further configured to: when the temperature value of the refrigerant is less than or equal to a third preset value and greater than a fourth preset value, if the current frequency of the compressor is lower than the target frequency of the compressor, control the compressor to increase its frequency at a first rate; if the current frequency of the compressor is greater than the target frequency of the compressor, control the compressor to adjust its frequency at a preset rate; if the current frequency of the compressor is equal to the target frequency of the compressor, control the compressor to maintain its current frequency; wherein the first rate is less than the preset rate.

[0021] In some embodiments, the controller is further configured to: when controlling the compressor frequency to decrease, if the temperature value of the refrigerant is greater than a second preset value and less than or equal to a fifth preset value, then control the compressor frequency to decrease at a second rate; if the temperature value of the refrigerant is greater than a fifth preset value and less than or equal to a first preset value, then control the compressor frequency to decrease at a third rate; wherein the third rate is greater than or equal to the second rate.

[0022] This application also provides an air conditioner, including:

[0023] Indoor heat exchanger, used for exchanging heat with indoor air;

[0024] An outdoor heat exchanger is used to exchange heat with outdoor air.

[0025] The compressor, together with the indoor heat exchanger and the outdoor heat exchanger, forms a refrigerant circulation loop. Refrigerant flows in the refrigerant circulation loop. The compressor is used to compress low-pressure refrigerant gas into high-pressure refrigerant gas and drive the refrigerant to flow in the refrigerant circulation loop.

[0026] A refrigerant temperature sensor is installed in the refrigerant circulation loop to detect the temperature of the refrigerant.

[0027] The controller is connected to the compressor and refrigerant temperature sensor respectively; the controller is configured as follows:

[0028] Regularly obtain the detection information from the refrigerant temperature sensor;

[0029] When the refrigerant temperature is less than or equal to the fourth preset value, the compressor frequency is adjusted according to the current operating conditions of the air conditioner.

[0030] When the temperature of the refrigerant exceeds the first preset value, the shutdown protection is activated, and the compressor is stopped.

[0031] When the temperature of the refrigerant is greater than the fourth preset value and less than or equal to the third preset value, slow frequency ramp protection is activated.

[0032] When the temperature value of the refrigerant is greater than the third preset value and less than the first preset value, the temperature change trend of the refrigerant is further determined based on the obtained temperature value of the refrigerant.

[0033] If the refrigerant temperature shows a downward trend, the frequency increase prevention protection will be activated, preventing the compressor frequency from increasing;

[0034] If the refrigerant temperature shows an upward trend, when the refrigerant temperature is greater than the second preset value, frequency reduction protection is activated, controlling the compressor frequency to decrease; when the refrigerant temperature is less than or equal to the second preset value, frequency increase prevention protection is activated, preventing the compressor frequency from increasing.

[0035] In some embodiments, when the temperature of the refrigerant is greater than a first preset value and the temperature of the refrigerant shows an upward trend, the temperature of the refrigerant will continue to rise by a certain value after the compressor stops running and then decrease.

[0036] In some embodiments, the controller is further configured to: determine that the temperature of the refrigerant is trending upward if the temperature value of the newly acquired refrigerant is greater than the temperature value of the previously acquired refrigerant; and determine that the temperature of the refrigerant is trending downward if the temperature value of the newly acquired refrigerant is less than the temperature value of the previously acquired refrigerant.

[0037] In some embodiments, the refrigerant temperature sensor includes a first temperature sensor and a second temperature sensor. The first temperature sensor is located in the connecting pipe of the outdoor heat exchanger, and the second temperature sensor is located in the connecting pipe of the indoor heat exchanger. The controller is configured to acquire the detection information of the first temperature sensor when the outdoor heat exchanger is operating as a condenser, and to acquire the detection information of the second temperature sensor when the indoor heat exchanger is operating as a condenser.

[0038] This technical solution protects the air conditioning system by installing a refrigerant temperature sensor to detect the temperature of the refrigerant under high pressure.

[0039] The aforementioned air conditioner has formulated various protection strategies to address the severity of adverse consequences when the air conditioning system malfunctions, and has also defined corresponding triggering conditions for these protection strategies. By determining which protection strategy's triggering condition the refrigerant temperature meets, the corresponding protection strategy is executed to protect the air conditioning system, thereby ensuring the stability and reliability of the air conditioning system's operation. Attached Figure Description

[0040] Figure 1 A schematic diagram of refrigerant flow is shown when an air conditioner is in cooling mode according to some embodiments;

[0041] Figure 2 A schematic diagram of refrigerant flow is shown when an air conditioner is in heating mode according to some embodiments;

[0042] Figure 3 An exemplary diagram showing the relationship between refrigerant temperature and protection strategy in the air conditioner of this application is provided;

[0043] Figure 4A flowchart illustrating the determination of refrigerant temperature change trend in the air conditioner according to this application is shown;

[0044] Figure 5 An exemplary flowchart of the first embodiment of the air conditioner of this application is shown;

[0045] Figure 6 An exemplary control principle diagram of the compressor in the first embodiment of the air conditioner of this application is shown;

[0046] Figure 7 An exemplary flowchart of the second embodiment of the air conditioner of this application is shown;

[0047] Figure 8 An exemplary flowchart of the third embodiment of the air conditioner of this application is shown;

[0048] Figure 9 An exemplary flowchart of the fourth embodiment of the air conditioner of this application is shown;

[0049] Figure 10 An exemplary flowchart of the fifth embodiment of the air conditioner of this application is shown;

[0050] Figure 11 An exemplary flowchart illustrates the slow frequency reduction and fast frequency reduction processes in the air conditioner of this application.

[0051] Figure 12 An exemplary control principle diagram of the air conditioner of this application is shown. Detailed Implementation

[0052] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0053] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0054] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0055] The terms “include” and “have”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0056] The air conditioner provided in this application is an inverter air conditioner. Inverter air conditioners can have various implementation forms, such as wall-mounted units, floor-standing units, ceiling-mounted units, etc.

[0057] An air conditioner includes an indoor heat exchanger, which is located indoors and used to exchange heat with indoor air, thereby heating or cooling the indoor environment.

[0058] An air conditioner includes an outdoor heat exchanger, which is located outdoors and used to exchange heat with outdoor air.

[0059] An air conditioner includes a compressor, an outdoor heat exchanger, and an indoor heat exchanger, which together form a refrigerant circulation loop. The compressor is used to compress the refrigerant from a low-pressure state to a high-pressure state and drive the refrigerant to circulate in the refrigerant circulation loop so that the indoor heat exchanger can cool or heat the indoor air.

[0060] like Figure 1 As shown, when an air conditioner cools the indoor environment, the outdoor heat exchanger acts as a condenser, and the indoor heat exchanger acts as an evaporator. The refrigerant, after being compressed by the compressor, flows into the outdoor heat exchanger to release heat, then flows into the indoor heat exchanger to absorb heat, and finally flows back into the compressor.

[0061] like Figure 2 As shown, when the air conditioner heats the indoor environment, the outdoor heat exchanger acts as the evaporator, and the indoor heat exchanger acts as the condenser. The refrigerant, after being compressed by the compressor, flows into the indoor heat exchanger to release heat, then flows into the outdoor heat exchanger to absorb heat, and finally flows back into the compressor.

[0062] The refrigerant circulation loop includes a high-pressure pipeline, in which refrigerant in a high-pressure state flows. The pipeline connected to the condenser is a high-pressure pipeline.

[0063] The refrigerant circulation loop includes a low-pressure pipeline, in which refrigerant flows at low pressure, and the pipeline connected to the evaporator is also a low-pressure pipeline.

[0064] In some embodiments, high-pressure pipelines and low-pressure pipelines are classified according to the pressure inside the pipeline.

[0065] An air conditioner includes an expansion valve located in the refrigerant circulation loop. The expansion valve causes the high-temperature, high-pressure liquid refrigerant condensed in the condenser to expand into a low-pressure liquid refrigerant.

[0066] An air conditioner includes a controller, which is connected to the compressor and is used to control the operation of the compressor.

[0067] The controller adjusts the compressor's operating frequency according to indoor temperature requirements to ensure the air conditioner's cooling or heating performance.

[0068] Indoor temperature demand usually refers to the cooling or heating capacity required to reach the set indoor temperature.

[0069] In some embodiments of this application, the air conditioner includes an indoor temperature sensor, which is located indoors and is used to detect the indoor ambient temperature.

[0070] The indoor temperature sensor is connected to the controller, which is configured to acquire the detection information from the indoor temperature sensor and calculate the indoor temperature requirement based on the detection information from the indoor temperature sensor and the set temperature of the air conditioning system.

[0071] It should be noted that methods for calculating indoor temperature requirements include, but are not limited to, calculating indoor ambient temperature and the set temperature of the air conditioning system. The calculation of indoor temperature requirements is a conventional technique in this field and will not be elaborated here.

[0072] The air conditioner includes a refrigerant temperature sensor, which is located in the refrigerant circulation loop and is used to detect the temperature of the refrigerant.

[0073] The refrigerant temperature sensor is connected to the controller, and the controller obtains the refrigerant temperature value T by acquiring the detection information from the refrigerant temperature sensor.

[0074] In some embodiments, a refrigerant temperature sensor is installed inside the high-pressure pipeline to detect the temperature of the refrigerant inside the high-pressure pipeline.

[0075] When the refrigerant temperature sensor is located inside the high-pressure pipeline, the refrigerant temperature sensor includes a first temperature sensor, which is located inside the outdoor heat exchanger connection pipeline. When the air conditioning system cools the indoor environment, the outdoor heat exchanger operates as a condenser, and the controller acquires the detection information from the first temperature sensor.

[0076] The refrigerant temperature sensor includes a second temperature sensor, which is located in the connecting pipe of the indoor heat exchanger. When the air conditioning system heats the indoor environment, the indoor heat exchanger operates as a condenser, and the controller acquires the detection information from the second temperature sensor.

[0077] During the operation of an air conditioning system, if the refrigerant temperature is too high, the compressor frequency needs to be reduced to avoid excessive refrigerant pressure. However, if the frequency is reduced too slowly, the refrigerant pressure may continue to rise, damaging the compressor. If the frequency is reduced too quickly, the pressure within the system may fluctuate, causing instability in the entire air conditioning system, resulting in a poor user experience or even damaging the air conditioner.

[0078] In this application, different protection strategies are formulated based on whether the air conditioning system may malfunction and the severity of the adverse consequences that may result from malfunction, in order to regulate the frequency of the compressor; and corresponding protection strategies are adopted to regulate the frequency of the compressor according to the current operating conditions of the air conditioning system, thereby ensuring the stability of the air conditioning system.

[0079] The air conditioning system includes a shutdown protection mechanism. When the refrigerant temperature is too high, the air conditioning system may malfunction, and the adverse consequences of such malfunctions can be quite serious. By stopping the compressor, the refrigerant stops flowing in the refrigerant circulation loop, preventing the refrigerant temperature from continuing to rise and / or the refrigerant pressure from continuing to increase, thereby preventing the air conditioning system from becoming unstable or damaged.

[0080] The air conditioning system includes frequency reduction protection. When the refrigerant temperature is high, the air conditioning system may malfunction, and the adverse consequences of such malfunctions are relatively serious. By controlling the compressor to reduce its operating frequency, the flow rate of the refrigerant in the refrigerant circulation loop is reduced, preventing the refrigerant temperature from continuing to rise and / or the refrigerant pressure from continuing to increase, thereby preventing the air conditioning system from becoming unstable or damaged.

[0081] The air conditioning system includes a frequency-prevention protection mechanism. When the refrigerant temperature is relatively high, the air conditioning system may malfunction, and such malfunctions can have serious adverse consequences. Although maintaining the current compressor frequency usually does not cause the air conditioning system to malfunction, increasing the compressor frequency may lead to an increase in refrigerant temperature and / or a continued increase in refrigerant pressure. Therefore, by preventing the compressor frequency from increasing, the continued increase in refrigerant temperature and / or refrigerant pressure is prevented, thereby preventing the air conditioning system from becoming unstable or damaged.

[0082] The air conditioning system includes a slow-speed frequency ramp-up protection feature. While the system may malfunction when the refrigerant temperature is slightly high, the adverse consequences are relatively minor. If the compressor's current frequency is lower than its target frequency under current operating conditions, the system controls the compressor to slowly ramp up at a first rate V1 to prevent further increases in refrigerant temperature and / or pressure, which could lead to system instability or damage. It should be noted that during normal operation, the controller regulates the compressor's frequency at a preset rate V0, and the first rate V1 is lower than the preset rate V0.

[0083] It should be noted that the shutdown protection, frequency reduction protection, frequency increase prohibition protection, and slow frequency increase protection correspond to the severity of the adverse consequences when the air conditioning system malfunctions.

[0084] In this application, corresponding triggering conditions are formulated for different protection strategies. By judging whether the temperature value T of the refrigerant meets the triggering conditions of the protection strategy, when the triggering conditions of a certain protection strategy are met, the air conditioning system adopts the corresponding protection strategy to regulate the frequency of the compressor, thereby ensuring the stability of the air conditioning system.

[0085] like Figure 3 As shown, the shutdown protection is triggered when the refrigerant temperature T is greater than the first preset value T1. It should be noted that the first preset value T1 can also be considered the compressor's shutdown temperature point.

[0086] That is, the controller is configured to perform shutdown protection when the temperature value T of the refrigerant is greater than the first preset value T1.

[0087] The controller is further configured to stop the compressor when a shutdown protection is executed.

[0088] It should be noted that after the compressor stops running, the refrigerant continues to flow in the refrigerant circulation loop for a certain period of time due to inertia. Therefore, the compressor's shutdown temperature point, i.e., the first preset value, is usually not higher than the refrigerant's maximum temperature. When the refrigerant temperature T is greater than the first preset value T1 and the refrigerant temperature shows an upward trend, the refrigerant temperature will continue to rise to a certain value after the compressor stops running, and then decrease. When the refrigerant temperature T is greater than the first preset value T1 and the refrigerant temperature shows a downward trend, the refrigerant temperature will continue to decrease after the compressor stops running.

[0089] In this application, when the temperature value T of the refrigerant is less than the threshold, the controller will control the compressor to restart.

[0090] That is, the controller is configured to: control the compressor to stop running when the shutdown protection is executed, and control the compressor to restart when the refrigerant temperature is lower than a certain threshold.

[0091] In some embodiments, the threshold is a third preset value T3.

[0092] The trigger condition for frequency throttling protection is: the refrigerant temperature T is less than or equal to the first preset value T1 and greater than the second preset value T2. It should be noted that the second preset value T2 can also be considered as the compressor's frequency throttling temperature point.

[0093] That is, the controller is configured to perform frequency reduction protection when the temperature value T of the refrigerant is less than or equal to the first preset value T1 and greater than the second preset value T2.

[0094] The controller is further configured to control the compressor to reduce its operating frequency when frequency reduction protection is activated.

[0095] The triggering conditions for the frequency increase prohibition protection vary depending on the trend of refrigerant temperature change. When the refrigerant temperature shows a decreasing trend, the triggering condition for the frequency increase prohibition protection is: the refrigerant temperature value T is greater than the third preset value T3. When the refrigerant temperature shows an increasing trend, the triggering condition for the frequency increase prohibition protection is: the refrigerant temperature value T is less than or equal to the second preset value T2 and greater than the third preset value T3. It should be noted that the third preset value T3 can also be considered as the compressor's frequency increase prohibition temperature point.

[0096] That is, the controller is configured to: when the temperature of the refrigerant is decreasing, if the temperature value T of the refrigerant is greater than the third preset value T3, then the frequency upscaling protection is executed; when the temperature of the refrigerant is increasing, if the temperature value T of the refrigerant is less than or equal to the second preset value T2 and greater than the third preset value T3, then the frequency upscaling protection is executed.

[0097] The controller is further configured to: when the frequency increase prohibition protection is executed, if the current frequency of the compressor is lower than or equal to the target frequency of the compressor under the current operating conditions of the air conditioner, the controller controls the compressor to maintain the current frequency; if the current frequency of the compressor is higher than the target frequency of the compressor under the current operating conditions of the air conditioner, the controller reduces the current frequency of the compressor according to the target frequency.

[0098] The trigger condition for slow frequency ramp-up protection is: the refrigerant temperature T is greater than the fourth preset value T4 and less than or equal to the third preset value T3. It should be noted that the fourth preset value T4 can also be considered as the slow frequency ramp-up temperature point of the compressor.

[0099] That is, the controller is configured to execute slow frequency ramp protection when the temperature value T of the refrigerant is greater than the fourth preset value T4 and less than or equal to the third preset value T3.

[0100] The controller is further configured to: when performing slow frequency ramp-up protection, if the current frequency of the compressor is lower than the target frequency of the compressor, the controller controls the compressor to ramp up the frequency at a first rate V1; if the current frequency of the compressor is greater than the target frequency of the compressor, the controller controls the compressor to adjust the frequency at a preset rate V0; if the current frequency of the compressor is equal to the target frequency of the compressor, the controller controls the compressor to maintain the current frequency.

[0101] When the refrigerant temperature T is less than or equal to the fourth preset value T4, the air conditioning system will usually not malfunction and will not need to perform protection. The controller will adjust the compressor frequency according to the current operating conditions of the air conditioner.

[0102] It can be assumed that when the refrigerant temperature T is less than or equal to the fourth preset value T4, the air conditioning system does not need to perform protection; when the refrigerant temperature T is greater than the fourth preset value T4, the air conditioning system needs to perform protection.

[0103] Alternatively, it can be considered that whether the refrigerant temperature value T is greater than the fourth preset value T4 is a judgment on whether the air conditioning system needs protection or whether the air conditioning system may malfunction.

[0104] It should be noted that when the refrigerant temperature T does not meet any trigger condition, the air conditioning system does not need to perform protection, that is, the air conditioning system is in normal working condition; when the refrigerant temperature T is less than or equal to the fourth preset value T4, the air conditioning system also does not need to perform protection. Therefore, whether the air conditioning system activates protection can be determined by judging whether the refrigerant temperature T meets a certain trigger adjustment condition, or by judging whether the refrigerant temperature T is greater than the fourth preset value T4.

[0105] In some embodiments of this application, the first preset value T1 > the second preset value T2, the second preset value T2 > the fifth preset value T5, the fifth preset value T5 > the third preset value T3, and the third preset value T3 > the fourth preset value T4.

[0106] In this application, by setting a slow-rise temperature point, a prohibited-rise temperature point, a slow-fall temperature point, a fast-fall temperature point, and a shutdown temperature point for the compressor frequency, trigger conditions for slow-rise protection, prohibited-rise protection, slow-fall protection, fast-fall protection, and shutdown protection are formed. By using the current refrigerant temperature value T and the refrigerant temperature change trend, the trigger conditions satisfied by the current refrigerant temperature value T are determined, and the corresponding protection strategy is executed to protect the air conditioning system and ensure the stability and reliability of the air conditioning system.

[0107] like Figure 4 As shown, the method for judging the trend of refrigerant temperature change is as follows: if the newly obtained temperature value is greater than the previously obtained temperature value, the refrigerant temperature value T is determined to be on an upward trend; if the newly obtained temperature value is less than the previously obtained temperature value, the refrigerant temperature value T is determined to be on a downward trend.

[0108] In some embodiments, the temperature accuracy for both the upward and downward trends is 1°C.

[0109] The order in which the trigger conditions for shutdown protection, frequency reduction protection, frequency increase prohibition protection, and slow frequency increase protection are determined is not fixed and can be randomly combined.

[0110] In the first embodiment of this application, it is first determined whether the temperature value T of the refrigerant meets the triggering condition of the shutdown protection. Then, based on the change trend of the refrigerant temperature, it is determined whether the temperature value T of the refrigerant meets the triggering conditions of frequency reduction protection, frequency increase prohibition protection, and slow frequency increase protection. If the temperature value T of the refrigerant does not meet any of the triggering conditions, the air conditioning system does not need protection.

[0111] Specifically, such as Figure 5 and Figure 6 As shown, the controller is configured to periodically acquire the temperature value T of the refrigerant; when the temperature value T of the refrigerant is greater than the first preset value T1, execute the shutdown protection and control the compressor to stop running; when the refrigerant temperature is lower than the threshold, control the compressor to restart.

[0112] When the temperature value T of the refrigerant is less than or equal to the first preset value T1, the temperature change trend of the refrigerant is further determined based on the obtained temperature value T of the refrigerant.

[0113] If the refrigerant temperature shows an upward trend, when the refrigerant temperature T is greater than the second preset value T2, frequency reduction protection is activated, controlling the compressor frequency to decrease; when the refrigerant temperature T is less than or equal to the second preset value T2 and greater than the third preset value T3, frequency increase prohibition protection is activated, prohibiting the compressor frequency from increasing; when the refrigerant temperature T is greater than the fourth preset value T4 and less than or equal to the third preset value T3, slow frequency increase protection is activated. If the current compressor frequency is lower than the compressor's target frequency under the current operating conditions of the air conditioner, the compressor is controlled to increase its frequency at the first rate V1; if the current compressor frequency is greater than the compressor's target frequency, the compressor is controlled to adjust its frequency at the preset rate V0; if the current compressor frequency is equal to the compressor's target frequency, the compressor is controlled to maintain its current frequency; wherein, the first rate V1 is less than the preset rate V0; when the refrigerant temperature T is less than or equal to the fourth preset value T4, protection is not required, and the compressor frequency is adjusted according to the current operating conditions of the air conditioner.

[0114] If the refrigerant temperature shows a decreasing trend, when the refrigerant temperature T is greater than the third preset value T3, frequency increase prohibition protection is activated, preventing the compressor frequency from increasing; when the refrigerant temperature T is less than or equal to the third preset value T3 but greater than the fourth preset value T4, slow frequency increase protection is activated. If the current compressor frequency is lower than the compressor target frequency under the current operating conditions of the air conditioner, the controller controls the compressor to slowly increase the frequency at the first rate V1; if the current compressor frequency is greater than or equal to the compressor target frequency, the compressor current frequency is adjusted according to the compressor target frequency under the current operating conditions of the air conditioner; when the refrigerant temperature T is less than or equal to the fourth preset value T4, protection is not required, and the compressor current frequency is adjusted according to the current operating conditions of the air conditioner.

[0115] The first embodiment of this application can protect the air conditioning system in a timely manner when an abnormality occurs, and can minimize the damage to the air conditioning system.

[0116] In the first embodiment of this application, the air conditioning system only operates normally after ruling out possible abnormal operation, resulting in high stability and good protection. However, since the probability of an air conditioning system malfunctioning is relatively small, this process design can easily reduce the response speed of the air conditioning system.

[0117] In the first embodiment of this application, the system determines whether the refrigerant temperature value T meets the trigger conditions for shutdown protection, frequency reduction protection, frequency increase prohibition protection, and slow frequency increase protection. If the refrigerant temperature value T meets a certain trigger condition, the corresponding protection is executed to ensure the reliability and stability of the air conditioning system. If the refrigerant temperature value T does not meet any trigger condition, the air conditioning system does not require protection.

[0118] In the second embodiment of this application, it is first determined whether the air conditioning system may malfunction, then it is determined whether there is a risk of the air conditioning system malfunctioning, and the triggering conditions for corresponding protection are determined according to the severity of the adverse consequences caused when the air conditioning system malfunctions.

[0119] Specifically, such as Figure 7 As shown, the controller is configured to periodically acquire detection information from the refrigerant temperature sensor;

[0120] When the refrigerant temperature T is less than or equal to the fourth preset value T4, the air conditioning system is in normal working condition. At this time, protection is not required. The controller adjusts the compressor's current frequency according to the compressor's target frequency under the current operating conditions of the air conditioner.

[0121] When the temperature value T of the refrigerant is greater than the fourth preset value T4 and less than or equal to the third preset value T3, slow frequency ramp protection is activated.

[0122] When the temperature value T of the refrigerant is greater than the first preset value T1, the shutdown protection is activated, and the compressor is controlled to stop running.

[0123] When the temperature value T of the refrigerant is greater than the third preset value T3 and less than or equal to the first preset value T1, the temperature change trend of the refrigerant is further judged based on the obtained temperature value T of the refrigerant.

[0124] If the refrigerant temperature shows a downward trend, the frequency increase prevention protection will be activated, preventing the compressor frequency from increasing;

[0125] If the refrigerant temperature shows an upward trend, when the refrigerant temperature T is greater than the second preset value T2, frequency reduction protection is activated, controlling the compressor frequency to decrease; when the refrigerant temperature T is less than or equal to the second preset value T2, frequency increase prevention protection is activated, preventing the compressor frequency from increasing.

[0126] The second embodiment of this application determines whether the air conditioning system may malfunction based on the temperature value T of the refrigerant. Based on the severity of the adverse consequences caused by the malfunction of the air conditioning system and the trend of refrigerant temperature change, a corresponding protection strategy is adopted to regulate the frequency of the compressor according to the current operating condition of the air conditioning system, thereby ensuring the stability of the air conditioning system.

[0127] The second embodiment of this application enables the air conditioning system to respond promptly and improve work efficiency.

[0128] In the third embodiment of this application, it is first determined whether the air conditioning system may malfunction, then it is determined whether the air conditioning system may have a risk of malfunction, and then the temperature value T of the refrigerant is determined in sequence to meet the trigger conditions of slow frequency increase protection, frequency increase prohibition protection, and frequency reduction protection.

[0129] Specifically, such as Figure 8 As shown, the controller is configured to periodically acquire detection information from the refrigerant temperature sensor;

[0130] When the refrigerant temperature T is less than or equal to the fourth preset value T4, the air conditioning system is in normal working condition. At this time, protection is not required. The controller adjusts the compressor's current frequency according to the compressor's target frequency under the current operating conditions of the air conditioner.

[0131] When the temperature value T of the refrigerant is greater than the fourth preset value T4 and less than or equal to the third preset value T3, slow frequency ramp protection is activated.

[0132] When the temperature value T of the refrigerant is greater than the third preset value T3, the temperature change trend of the refrigerant is further judged based on the obtained temperature value T of the refrigerant.

[0133] If the refrigerant temperature shows an upward trend, when the refrigerant temperature value T is less than or equal to the second preset value T2, frequency increase protection is executed; when the refrigerant temperature value T is greater than the second preset value T2 but less than or equal to the first preset value T1, frequency decrease protection is executed; when the refrigerant temperature value T is greater than the first preset value T1, shutdown protection is executed.

[0134] If the refrigerant temperature shows a downward trend, the protection will not be activated, and the compressor frequency will be adjusted according to the compressor target frequency under the current operating conditions of the air conditioning system.

[0135] In the third embodiment of this application, the slow frequency increase trigger condition is determined first, and then the refrigerant temperature change trend is determined. Therefore, when the air conditioning system needs to perform slow frequency increase protection, the start-up efficiency of slow frequency increase protection can be increased.

[0136] In the fourth embodiment of this application, it is first determined whether the air conditioning system meets the triggering conditions for shutdown protection, then it is determined whether the air conditioning system may malfunction, and then the triggering conditions for slow frequency increase protection, frequency increase prohibition protection, and frequency reduction protection are determined in sequence.

[0137] Specifically, such as Figure 9 As shown, the controller is configured to periodically acquire detection information from the refrigerant temperature sensor;

[0138] When the temperature value T of the refrigerant is greater than the first preset value T1, the shutdown protection is activated.

[0139] When the refrigerant temperature T is less than or equal to the fourth preset value T4, the air conditioning system is in normal working condition. At this time, protection is not required. The controller adjusts the compressor's current frequency according to the compressor's target frequency under the current operating conditions of the air conditioner.

[0140] When the temperature value T of the refrigerant is greater than the fourth preset value T4 and less than or equal to the third preset value T3, slow frequency ramp protection is activated.

[0141] When the temperature value T of the refrigerant is greater than the third preset value T3, the temperature change trend of the refrigerant is further judged based on the obtained temperature value T of the refrigerant.

[0142] If the refrigerant temperature shows a downward trend, the protection will not be activated, and the compressor frequency will be adjusted according to the compressor target frequency under the current operating conditions of the air conditioning system.

[0143] If the refrigerant temperature shows an upward trend, when the refrigerant temperature T is greater than the second preset value T2, frequency reduction protection is activated, controlling the compressor frequency to decrease; when the refrigerant temperature T is less than or equal to the second preset value T2, frequency increase prevention protection is activated, preventing the compressor frequency from increasing.

[0144] The fourth embodiment of this application can promptly execute shutdown protection when the air conditioning system meets the shutdown protection trigger conditions to prevent major damage to the air conditioning system; after determining whether to execute shutdown protection, it is determined whether the air conditioning system may malfunction. When the air conditioning system will not malfunction, it can enable the air conditioning system to operate normally in a timely manner, thereby ensuring that the air conditioning system has a high response speed.

[0145] In the fifth embodiment of this application, based on the trend of refrigerant temperature change, it is determined whether the air conditioning system may malfunction, and then the triggering conditions are determined according to the severity of the malfunction.

[0146] Specifically, such as Figure 10 As shown, the controller is configured to periodically acquire the temperature value T of the refrigerant and determine the temperature change trend of the refrigerant based on the acquired temperature value T.

[0147] If the refrigerant temperature shows an upward trend, when the refrigerant temperature T is greater than the first preset value T1, the shutdown protection is executed, controlling the compressor to stop running; when the refrigerant temperature T is less than or equal to the first preset value T1 and greater than the second preset value T2, the frequency reduction protection is executed, controlling the compressor frequency to decrease; when the refrigerant temperature T is less than or equal to the second preset value T2 and greater than the third preset value T3, the frequency increase prohibition protection is executed, prohibiting the compressor frequency from increasing; when the refrigerant temperature T is greater than the fourth preset value T4 and less than or equal to the third preset value T3, the slow frequency increase protection is executed.

[0148] If the refrigerant temperature shows a downward trend, when the refrigerant temperature value T is greater than the first preset value T1, the shutdown protection is executed, and the compressor is controlled to stop running; when the refrigerant temperature value T is less than or equal to the first preset value T1 and greater than the third preset value T3, the frequency increase prohibition protection is executed, and the compressor frequency is prohibited from increasing; when the refrigerant temperature value T is greater than the fourth preset value T4 and less than or equal to the third preset value T3, the slow frequency increase protection is executed.

[0149] In this application, such as Figure 11 As shown, when the air conditioning system performs frequency reduction protection, it is further subdivided into fast frequency reduction protection and slow frequency reduction protection based on the refrigerant temperature. Specifically, the rate of compressor frequency reduction is greater when fast frequency reduction protection is performed than when slow frequency reduction protection is performed.

[0150] The slow frequency reduction protection is triggered when the refrigerant temperature T is greater than the second preset value T2 and less than or equal to the fifth preset value T5. It should be noted that the fifth preset value T2 can be considered the compressor's slow frequency reduction temperature point.

[0151] That is, the controller is configured to perform slow frequency reduction protection when the temperature value T of the refrigerant is greater than the second preset value T2 and less than or equal to the fifth preset value T5.

[0152] The controller is further configured such that when slow frequency reduction protection is executed, the controller controls the compressor frequency to reduce the operating frequency at a second rate V2.

[0153] The trigger condition for rapid frequency reduction protection is: the refrigerant temperature T is greater than the fifth preset value T5 and less than or equal to the first preset value T1. The fifth preset value T5 can be regarded as the compressor's rapid frequency reduction temperature point.

[0154] That is, the controller is configured to perform fast frequency reduction protection when the temperature value T of the refrigerant is greater than the fifth preset value T5 and less than or equal to the first preset value T1.

[0155] The controller is further configured such that when fast frequency reduction protection is executed, the controller controls the compressor frequency to decrease at a third rate V3; wherein the third rate V3 is greater than or equal to the second rate V2.

[0156] In this application, the protections that the air conditioning system may perform when the refrigerant temperature changes with an upward trend include slow frequency increase protection, frequency increase prohibition protection, slow frequency decrease protection, slow frequency decrease protection, and shutdown protection. The protections that the air conditioning system may perform when the refrigerant temperature changes with a downward trend include slow frequency increase protection, frequency increase prohibition protection, and shutdown protection.

[0157] The control principle of the above air conditioning system is described in detail below. The first preset value T1 is greater than the second preset value T2, the second preset value T2 is greater than the fifth preset value T5, the fifth preset value T5 is greater than the third preset value T3, the third preset value T3 is greater than the fourth preset value T4, and the threshold is the third preset value T3.

[0158] like Figure 12 As shown, when the air conditioner is running, the controller obtains the detection information of the refrigerant temperature sensor every 5 seconds to obtain the temperature value T of the refrigerant. When the temperature value T of the refrigerant is greater than the first preset value T1, the shutdown protection is executed, and the compressor is controlled to stop running. When the temperature value T of the refrigerant drops to the third preset value T3, the compressor is controlled to restart.

[0159] When the refrigerant temperature value T is less than or equal to the first preset value T1, the newly acquired temperature value is compared with the previously acquired temperature value TS to determine the trend of refrigerant temperature change.

[0160] If the refrigerant temperature shows an upward trend, when the refrigerant temperature value T is less than or equal to the first preset value T1 and greater than the fifth preset value T5, rapid frequency increase protection is activated, controlling the compressor frequency to decrease at the third rate V3; when the refrigerant temperature value T is less than or equal to the fifth preset value T5 and greater than the second preset value T2, slow frequency increase protection is activated, controlling the compressor frequency to decrease at the second rate V2; when the refrigerant temperature value T is less than or equal to the second preset value T2 and greater than the third preset value T3, frequency increase prohibition protection is activated, controlling the compressor to maintain its current frequency when the current compressor frequency is lower than or equal to the compressor's target frequency under the current operating conditions of the air conditioner; when the compressor's current frequency... If the refrigerant temperature T is higher than the compressor's target frequency, the controller reduces the compressor's current frequency according to the target frequency. When the refrigerant temperature T is less than or equal to the third preset value T3 and greater than the fourth preset value T4, slow frequency increase protection is implemented. When the compressor's current frequency is lower than the compressor's target frequency under the current operating conditions of the air conditioner, the controller controls the compressor to slowly increase its frequency at the first rate V1. When the compressor's current frequency is greater than or equal to the compressor's target frequency, the controller adjusts the compressor's current frequency according to the compressor's target frequency under the current operating conditions of the air conditioner. When the refrigerant temperature T is less than or equal to the fourth preset value T4, the controller adjusts the compressor's current frequency according to the compressor's target frequency under the current operating conditions of the air conditioner.

[0161] If the refrigerant temperature shows a decreasing trend, when the refrigerant temperature T is greater than the third preset value T3, frequency increase prohibition protection is implemented. When the compressor's current frequency is lower than or equal to the compressor's target frequency under the current operating conditions of the air conditioner, the controller controls the compressor to maintain its current frequency. When the compressor's current frequency is higher than the compressor's target frequency under the current operating conditions of the air conditioner, the controller reduces the compressor's current frequency according to the compressor's target frequency under the current operating conditions of the air conditioner. When the refrigerant temperature T is less than or equal to the third preset value T3 and greater than the fourth preset value T4, slow frequency increase protection is implemented. When the compressor's current frequency is lower than the compressor's target frequency under the current operating conditions of the air conditioner, the controller controls the compressor to slowly increase its frequency at the first rate V1. When the compressor's current frequency is greater than or equal to the compressor's target frequency, the compressor's current frequency is adjusted according to the compressor's target frequency under the current operating conditions of the air conditioner. When the refrigerant temperature T is less than or equal to the fourth preset value T4, the compressor's current frequency is adjusted according to the compressor's target frequency under the current operating conditions of the air conditioner.

[0162] The aforementioned air conditioning system periodically acquires detection information from the refrigerant temperature sensor and compares the newly acquired refrigerant temperature value with the previously acquired refrigerant temperature value to determine the refrigerant temperature change trend. Based on the current refrigerant temperature and the refrigerant temperature change trend, it determines whether the air conditioning system needs to activate protection and what protection strategy to activate, thereby effectively protecting the air conditioning system and ensuring the stability and reliability of its operation.

[0163] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0164] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. An air conditioner characterized by comprising: The air conditioner comprises: an indoor heat exchanger for exchanging heat with indoor air; an outdoor heat exchanger for exchanging heat with outdoor air; a compressor, which, together with the indoor heat exchanger and the outdoor heat exchanger, forms a refrigerant circulation loop in which refrigerant flows, and which is configured to compress low-pressure refrigerant gas into high-pressure refrigerant gas and drive the refrigerant to flow in the refrigerant circulation loop; a refrigerant temperature sensor arranged in the refrigerant circulation loop and configured to detect the temperature of the refrigerant; a controller connected to the compressor and the refrigerant temperature sensor, respectively, and configured to: periodically obtain the temperature value of the refrigerant, and control the compressor to stop running when the temperature value of the refrigerant is greater than a first preset value; when the temperature value of the refrigerant is less than or equal to the first preset value, further judge the temperature variation trend of the refrigerant according to the obtained temperature value of the refrigerant; if the temperature of the refrigerant shows an upward trend, control the compressor frequency to decrease when the temperature value of the refrigerant is greater than a second preset value; when the temperature value of the refrigerant is less than or equal to the second preset value and greater than a third preset value, prohibit the compressor frequency from increasing; and when the temperature value of the refrigerant is less than or equal to the third preset value, adjust the compressor frequency according to the current operating condition of the air conditioner; if the temperature of the refrigerant shows a downward trend, prohibit the compressor frequency from increasing.

2. The air conditioner of claim 1, wherein The controller is further configured to control the compressor to restart running when the temperature value of the refrigerant is less than or equal to the third preset value after the compressor stops running.

3. The air conditioner of claim 1, wherein The controller is further configured to, when the temperature of the refrigerant shows a downward trend, prohibit the compressor frequency from increasing if the temperature value of the refrigerant is greater than the third preset value, and adjust the compressor frequency according to the current operating condition of the air conditioner if the temperature value of the refrigerant is less than or equal to the third preset value.

4. The air conditioner according to claim 1 or 3, wherein The controller is further configured to, when the compressor frequency is prohibited from increasing, control the compressor to maintain the current frequency if the current frequency of the compressor is lower than or equal to the target frequency of the compressor under the current operating condition of the air conditioner, and adjust the compressor frequency according to the target frequency if the current frequency of the compressor is higher than the target frequency.

5. The air conditioner of claim 1, wherein The controller is further configured to, when the temperature value of the refrigerant is less than or equal to the third preset value and greater than a fourth preset value, control the compressor to increase at a first rate if the current frequency of the compressor is lower than the target frequency of the compressor, control the compressor to adjust at a preset rate if the current frequency of the compressor is greater than the target frequency of the compressor, and control the compressor to maintain the current frequency if the current frequency of the compressor is equal to the target frequency of the compressor; wherein the first rate is less than the preset rate. The controller is further configured to, when the compressor frequency is controlled to decrease, control the compressor frequency to decrease at a second rate if the temperature value of the refrigerant is greater than the second preset value and less than or equal to a fifth preset value. ​ 6. The air conditioner of claim 1, wherein ​ If the temperature of the refrigerant is greater than the fifth preset value and less than or equal to the first preset value, the frequency of the compressor is controlled to decrease at a third rate; wherein the third rate is greater than or equal to the second rate.

7. An air conditioner characterized by comprising: The air conditioner comprises: an indoor heat exchanger for exchanging heat with indoor air; an outdoor heat exchanger for exchanging heat with outdoor air; a compressor, which, together with the indoor heat exchanger and the outdoor heat exchanger, forms a refrigerant circulation loop, wherein refrigerant flows in the refrigerant circulation loop, and the compressor is configured to compress low-pressure refrigerant gas into high-pressure refrigerant gas and drive the refrigerant to flow in the refrigerant circulation loop; a refrigerant temperature sensor arranged in the refrigerant circulation loop and configured to detect the temperature of the refrigerant; a controller connected to the compressor and the refrigerant temperature sensor, respectively; the controller is configured to: periodically acquire detection information of the refrigerant temperature sensor; when the temperature of the refrigerant is less than or equal to a fourth preset value, adjust the frequency of the compressor according to the current operating condition of the air conditioner; when the temperature of the refrigerant is greater than a first preset value, execute shutdown protection to control the compressor to stop running; when the temperature of the refrigerant is greater than the fourth preset value and less than or equal to a third preset value, execute slow frequency increase protection; when the temperature of the refrigerant is greater than the third preset value and less than the first preset value, further determine the temperature change trend of the refrigerant according to the acquired temperature value of the refrigerant; if the temperature of the refrigerant decreases, execute frequency increase prohibition protection to prohibit the frequency of the compressor from increasing; if the temperature of the refrigerant increases, when the temperature of the refrigerant is greater than a second preset value, execute frequency decrease protection to control the frequency of the compressor to decrease; when the temperature of the refrigerant is less than or equal to the second preset value, execute frequency increase prohibition protection to prohibit the frequency of the compressor from increasing.

8. The air conditioner according to claim 1 or 7, wherein When the temperature of the refrigerant is greater than the first preset value and the temperature of the refrigerant increases, the temperature of the refrigerant will continue to increase by a certain value and then decrease after the compressor stops running.

9. The air conditioner according to claim 1 or 7, wherein The controller is further configured to: if the newly acquired temperature value of the refrigerant is greater than the previously acquired temperature value of the refrigerant, determine that the temperature of the refrigerant increases; if the newly acquired temperature value of the refrigerant is less than the previously acquired temperature value of the refrigerant, determine that the temperature of the refrigerant decreases.

10. The air conditioner according to claim 1 or 7, wherein The refrigerant temperature sensor comprises a first temperature sensor and a second temperature sensor, the first temperature sensor is arranged in a connecting pipeline of the outdoor heat exchanger, and the second temperature sensor is arranged in a connecting pipeline of the indoor heat exchanger; the controller is configured to: when the outdoor heat exchanger works as a condenser, acquire the detection information of the first temperature sensor; and when the indoor heat exchanger works as a condenser, acquire the detection information of the second temperature sensor.

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