Air conditioner refrigerating system state recognition method, storage medium and air conditioner equipment

Abstract

The invention relates to the technical field of air conditioners, discloses an air conditioner refrigerating system state recognition method, a storage medium and air conditioner equipment, and solves the problems that in the prior art, the abnormal state of a refrigerating system cannot be accurately recognized, and misjudgment is likely to occur. According to the scheme, the maximum power value Powermax of the compressor within the time a after the compressor is started is recorded, and after the compressor continues to run for the time b, whether the abnormal state of the refrigerating system exists or not is preliminarily judged according to the current power and the Powermax; after continuous operation for c time, according to the difference value T1 between the indoor temperature and the temperature of the inner coil pipe and the difference value T2 between the temperature of the outer coil pipe and the outdoor temperature, the judgment process of entering loop blockage and serious loss of the refrigerant or the judgment process of refrigerant insufficiency is selected; for the refrigeration system, after the refrigeration system continues to run for d time, whether the refrigeration system is abnormally in loop blockage or severe loss of the refrigerant is judged according to the difference value T3 of the compressor motor winding temperature and the compressor exhaust temperature; and for the latter, after the air conditioner continues to run for d time, whether refrigerant insufficiency exists or not is judged according to T1 and T2.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an air conditioning refrigeration system state identification method, a storage medium and air conditioning equipment. Background Art

[0002] The abnormality of the air-conditioning refrigeration system accounts for a relatively high proportion in the after-sales maintenance category of air conditioners. The abnormality of the refrigeration system is somewhat different from the common refrigeration system failure. The refrigeration system failure refers more to hardware failures such as compressors. The air conditioner will not be able to operate due to system failures. This type of refrigeration system "hard failure" is easy to identify; while the abnormality of the refrigeration system is a "soft failure" of the refrigeration system. The abnormality of the refrigeration system may include blockage of the refrigeration system circuit and insufficient refrigerant. If these two types of refrigeration system abnormalities occur, the air conditioner can still operate at the beginning of startup. The characteristic phenomenon is that the refrigeration effect is not good. The potential risk is that the temperature of the motor winding of the compressor will gradually increase, and there is a risk of burning the compressor. Especially for the abnormal state of system circuit blockage in flammable refrigerant air conditioners, as the pressure gradually increases, it may also cause a combustion and explosion accident. Therefore, it is necessary to timely judge and identify the risks of abnormal refrigeration system, carry out corresponding protection and control, and ensure the reliability of the compressor.

[0003] The above-mentioned abnormal "soft fault" of the air conditioning refrigeration system, which is characterized by the blockage of the refrigeration system circuit and insufficient refrigerant, is characterized by poor refrigeration effect, poor evaporation effect, and low condensation superheat; however, the impact of these two types of abnormal soft faults on the refrigeration system is essentially different: the blockage of the refrigeration system circuit is due to the inability of the refrigerant to flow, and the internal winding of the compressor is not dissipated by the flow of refrigerant, which can easily cause the compressor winding temperature to be too high and burn out, or after the blockage, there is a leak on the low-pressure side of the system, which will continue to inhale air, and the blockage pressure on the high-pressure side rises sharply to the pressure limit, causing the risk of explosion of the compressor. Therefore, the blockage of the refrigeration system circuit needs to be identified in time and shut down for protection. However, insufficient refrigerant mostly means poor effect, and the compressor exhaust temperature rises to the protection limit and can be operated at a reduced frequency, and the high and low pressures of the system can circulate normally, and there is no risk of explosion caused by the system pressure reaching the compressor pressure limit. It can be operated with appropriate lack of refrigerant, unless it is completely missing or severely missing (such as missing to less than 50%), there is no evaporation and condensation at all, and shutdown protection is required. However, since the two types of problems have certain similarities, such as high evaporation temperature, low condensation superheat, and no obvious difference in exhaust temperature at the initial startup, the judgment of the two types of system abnormalities is easily confused.

[0004] At present, among the existing technologies in the industry, most of them are for judging and identifying insufficient refrigerant in air-conditioning systems, but they also have corresponding defects, as follows:

[0005] (1) In the patent application number CN201710773248.5, the relationship table between the exhaust temperature and the winding temperature is obtained by giving the expansion valve a fixed opening, so as to determine whether the refrigerant is insufficient. However, judging whether the refrigerant is insufficient only by the relationship table between the exhaust and winding temperatures is not accurate enough in many actual operation scenarios.

[0006] (2) In the patent with application number CN201510749524.5, the refrigerant shortage is determined by checking the difference between the outlet temperature of the outdoor refrigeration machine and the preset temperature. This scheme also has too few variables for judgment, and it is easy to confuse the blockage situation with the refrigerant shortage.

[0007] (3) In the patent with application number CN201911107479.8, the difference between the exhaust temperature and the preset value is checked after the machine is turned on. When the exhaust temperature is ≥ the preset value B for the first time, the machine needs to be shut down and the expansion valve opening needs to be adjusted. Then the difference is determined again to determine whether the refrigerant is insufficient. The disadvantage of this solution is that the machine needs to be shut down during the judgment process, which affects the user experience. In addition, the judgment is made only by exhausting one variable, which may result in low accuracy or misjudgment.

[0008] (4) In the patent with application number CN201811324409.3, by obtaining the first temperature of the indoor environment and the first evaporator temperature of the indoor evaporator, and obtaining the second indoor temperature of the indoor environment and the second evaporator temperature parameters of the indoor evaporator again after reaching the preset time, it is judged whether the refrigeration system is abnormal or whether the high and low pressure valves are open. The defect of this solution is that since the change of indoor evaporator temperature is similar to the refrigerant shortage when the refrigeration system circuit is blocked, it is easy to confuse the high-risk system circuit blockage with the refrigerant shortage, and it is easy to ignore the high-risk risk of system circuit blockage.

[0009] In summary, the existing technology cannot accurately identify the abnormal state of the refrigeration system and is prone to misjudgment. Summary of the invention

[0010] The technical problem to be solved by the present invention is to propose an air-conditioning refrigeration system status identification method, storage medium and air-conditioning equipment to solve the problem that the prior art cannot accurately identify the abnormal status of the refrigeration system and is prone to misjudgment.

[0011] The technical solution adopted by the present invention to solve the above technical problems is:

[0012] In a first aspect, the present invention provides a method for identifying the state of an air-conditioning refrigeration system, comprising the following steps:

[0013] S1. When the air conditioner is turned on and running in cooling or dehumidification mode for the first time, record the maximum power value of the air conditioner compressor within the first time;

[0014] S2, after the air conditioner continues to run for the second time, preliminarily determine whether there is an abnormal state of the refrigeration system according to the current power of the air conditioner compressor and the maximum power value in the first time, if so, proceed to step S3, otherwise, exit the determination process;

[0015] S3, after the air conditioner continues to run for a third time, selecting to enter a circuit blockage and severe refrigerant shortage judgment process or a refrigerant shortage judgment process according to the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature;

[0016] If the judgment process of circuit blockage and severe lack of refrigerant is entered, the process proceeds to step S4; if the judgment process of insufficient refrigerant is entered, the process proceeds to step S5;

[0017] S4, after the air conditioner continues to run for a fourth time, judging whether the abnormality of the refrigeration system is a circuit blockage or a serious lack of refrigerant based on the difference between the compressor motor winding temperature and the compressor exhaust temperature of the air conditioner;

[0018] S5. After the air conditioner continues to operate for a fourth time, determine whether there is a shortage of refrigerant based on the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature.

[0019] Further, in step S2, a preliminary determination is made as to whether there is an abnormal state of the refrigeration system according to the current power of the compressor of the air conditioner and the maximum power value within the first time, including:

[0020] JudgmentPower current ≤Power max *Whether K0 is established, if established, it is preliminarily determined that there is an abnormal state of the refrigeration system, if not established, it is determined that there is no abnormal state of the refrigeration system; among them, Power current is the current power of the air conditioner compressor, Power max is the maximum power value of the air conditioner compressor in the first time, and K0 is the preset coefficient.

[0021] Further, in step S3, the judgment process of circuit blockage and severe lack of refrigerant or the judgment process of insufficient refrigerant is selected according to the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature, including:

[0022] Determine whether △T1<K1 and △T2<K1 are established. If so, enter the judgment process of circuit blockage and severe lack of refrigerant. If not, enter the judgment process of insufficient refrigerant; wherein △T1 is the temperature difference between the indoor temperature and the inner coil temperature, △T2 is the temperature difference between the outer coil temperature and the outdoor temperature, and K1 is the first preset threshold.

[0023] Further, in step S4, judging whether the abnormality of the refrigeration system is a circuit blockage or a serious lack of refrigerant according to the difference between the compressor motor winding temperature and the compressor exhaust temperature of the air conditioner includes:

[0024] Determine whether △T3>K3 is established. If so, determine that the abnormality of the refrigeration system is a circuit blockage. If not, determine that the abnormality of the refrigeration system is a serious lack of refrigerant. Among them, △T3 is the difference between the compressor motor winding temperature and the compressor exhaust temperature of the air conditioner, and K3 is the third preset threshold.

[0025] Furthermore, the compressor motor winding temperature of the air conditioner adopts the estimated value of the compressor motor winding temperature.

[0026] Further, in step S5, judging whether there is insufficient refrigerant according to the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature includes:

[0027] Determine whether △T1<K2 and △T2<K2 are established. If so, it is determined that the refrigerant is insufficient. Otherwise, it is determined that the air-conditioning refrigeration system is in normal state; wherein △T1 is the temperature difference between the indoor temperature and the inner coil temperature, △T2 is the temperature difference between the outer coil temperature and the outdoor temperature, and K2 is the second preset threshold.

[0028] Furthermore, the first time is 30 to 60 seconds; the second time is 30 to 60 seconds; the third time is 180 to 240 seconds; the fourth time is 10 to 20 seconds; the value range of K0 is 0.85 to 0.65; K1 is preferably 3.5°C; K2 is preferably 5 to 8°C; K3 is preferably 10 to 11°C.

[0029] Further, step S4 also includes: if it is determined that the abnormality of the refrigeration system is a circuit blockage, the machine is immediately shut down for protection, and the circuit blockage abnormality is uploaded to the cloud server, reminding the after-sales personnel to come to the door for repair and treatment in time; if it is determined that the abnormality of the refrigeration system is a serious lack of refrigerant, the machine is shut down for protection, and the serious lack of refrigerant is uploaded to the cloud server, reminding the after-sales personnel to come to the door to replenish the refrigerant in time;

[0030] Step S5 also includes: if it is determined that there is a refrigerant shortage abnormality, the air conditioner continues to operate, and the refrigerant shortage abnormality information is uploaded to the cloud server for record backup, reminding after-sales personnel to choose an opportunity to visit the site to check for leaks and replenish refrigerant.

[0031] In a second aspect, the present invention further provides a storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for identifying the state of an air-conditioning refrigeration system as described above is implemented.

[0032] In a third aspect, the present invention further provides an air-conditioning device, which includes a processor and a memory, wherein the memory stores a computer program, and the processor implements the above-mentioned method for identifying the state of an air-conditioning refrigeration system by executing the computer program.

[0033] The beneficial effects of the present invention are:

[0034] The present invention comprehensively determines the state of the refrigeration system based on the power parameters of the air conditioner itself and the temperature estimated by the motor winding, combined with the exhaust temperature detected by the air conditioner's own sensor, the indoor and outdoor ambient temperature, the internal and external coil temperature and other multi-dimensional and multi-level parameters, and can accurately identify whether the abnormality of the refrigeration system is a high-risk system circuit blockage, or a common refrigerant shortage, or a serious lack of refrigerant; so that different protection measures can be adopted for different abnormal states. Since the solution of the present invention does not require hardware improvement, but is only implemented using software logic, it will not increase the product manufacturing cost and will not affect the manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a flow chart of a method for identifying a state of an air-conditioning refrigeration system in an embodiment of the present invention;

[0036] Figure 2 This is the air conditioning operating parameter curve diagram of the refrigeration system in Experimental Case 1, in which the small valve is closed before starting the refrigeration system to simulate the blockage of the system loop;

[0037] Figure 3 This is the normal startup and operation parameter curve of the air conditioner under the 50% refrigerant state in Experimental Case 2;

[0038] Figure 4 This is the normal startup and operation parameter curve of the air conditioner under 60% refrigerant state in experimental case 2. DETAILED DESCRIPTION

[0039] The present invention aims to provide an air-conditioning refrigeration system state identification method, a storage medium and an air-conditioning device, so as to solve the problem that the abnormal state of the refrigeration system cannot be accurately identified in the prior art and misjudgment is prone to occur. The core idea is: utilizing the physical characteristics of the compressor, the torque is large at the moment of starting. If the refrigeration system circuit is blocked or the refrigerant is seriously lacking, the no-load operating power of the compressor will drop rapidly and significantly, and the characteristics of circuit blockage and refrigerant shortage can be preliminarily determined; combined with the poor evaporation effect of the refrigeration system blockage and insufficient refrigerant, and the small condensation superheat, it is further determined whether there is a refrigeration system circuit blockage or refrigerant shortage; since the refrigeration system circuit blockage and the serious lack of refrigerant have very great similarities, the traditional technology cannot accurately determine whether it is a circuit blockage or a serious lack of refrigerant, and it is easy to confuse the two types of system abnormalities. The present invention adopts the compressor motor winding estimation technology, and compares the difference between the winding estimated temperature and the exhaust temperature with the preset threshold value, which can effectively determine and identify the circuit blockage or the serious lack of refrigerant; in addition, the present invention can also subdivide the refrigerant shortage into general refrigerant shortage or serious refrigerant shortage according to the comparison of the temperature difference between the indoor temperature and the inner coil temperature and the temperature difference between the outer coil temperature and the outdoor temperature with the two-level preset thresholds.

[0040] Therefore, the present invention can make accurate judgments based on the power parameters of the air conditioner itself and the temperature estimated by the motor windings, combined with multi-dimensional and multi-level parameters such as the exhaust temperature, indoor and outdoor ambient temperature, and internal and external coil temperature detected by the air conditioner's built-in sensors. It can not only distinguish and identify extremely dangerous system loop blockages from common refrigerant shortage system abnormalities, but can also further distinguish refrigerant shortages as serious deficiencies or general deficiencies, thereby accurately locating abnormal states of the refrigeration system, so as to adopt different protection measures for different abnormal states, thereby improving the safety of air conditioner operation, and providing effective guidance for after-sales services, thereby improving maintenance efficiency and reducing maintenance costs.

[0041] The scheme of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0042] Example

[0043] This embodiment provides a method for identifying the state of an air conditioning refrigeration system. Figure 1 , including the following steps:

[0044] S1. When the air conditioner is turned on and running in cooling or dehumidification mode for a time, record the maximum power value of the air conditioner compressor in a time. max ;

[0045] In this step, during the startup of the air conditioner, if the system circuit is blocked or the valve is not opened, the power of the whole machine will reach the maximum value at the moment when the compressor starts with a large torque. After that, due to the lack of refrigerant flow, the compressor runs at no load, and its power will drop significantly. Even if the frequency rises, its power is more than 10% lower than the peak value at startup. Therefore, by recording the maximum power value Power within a time max The peak power value at startup is used as the basis for subsequent power comparisons.

[0046] Considering the process from the air conditioner being turned on to stable operation, the a time here is preferably 30 to 60 seconds.

[0047] S2, after the air conditioner continues to run for b time, determine the power current ≤Power max *Whether K0 is established, if so, proceed to step S3, otherwise, determine that the air conditioner is operating normally and exit the process;

[0048] In this step, after the air conditioner continues to run for b time (preferably 30 to 60 seconds), the air conditioner MCU reads the current power again. current , determine whether one of the abnormal conditions of the refrigeration system meets the Power current ≤Power max *K0, that is, to judge whether the current power fluctuates greatly by this condition, K0 is a preset coefficient, preferably 0.85 to 0.65. If this condition is met, it can be preliminarily judged that there is an abnormal state of the system, and then enter step S3 for further specific judgment.

[0049] S3, after the air conditioner continues to run for c time, determine whether △T1<K1 and △T2<K1 are established. If so, select to enter the judgment process of circuit blockage and severe lack of refrigerant and enter step S4. If not, select to enter the judgment process of insufficient refrigerant and enter step S5.

[0050] In this step, after the air conditioner continues to run for c time (preferably 180 to 240S), the temperature difference △T1 between the indoor temperature and the inner coil temperature, as well as the temperature difference △T2 between the outer coil temperature and the outdoor temperature are compared with the first preset threshold value K1 to determine whether the circuit is blocked and the refrigerant is seriously lacking.

[0051] Since the evaporation effect is poor and the evaporation temperature is high when the circuit is blocked or the refrigerant is seriously lacking, the temperature difference △T1 between the indoor temperature and the inner coil temperature is small, and there is basically no condensation superheat, so the difference △T2 between the outdoor coil temperature and the outdoor temperature is also small. Therefore, a smaller first preset threshold K1 can be set, preferably 3.5℃; that is, if △T1<3.5℃ and △T2<3.5℃, it can be determined that there is a circuit blockage or a serious lack of refrigerant, but it is necessary to enter step S4 for further determination of which specific abnormality it belongs to. If the above conditions are not met, the judgment process of insufficient refrigerant in step S5 is entered.

[0052] It should be noted that a refrigerant content below about 70% is usually defined as a general refrigerant shortage, i.e., "refrigerant shortage" in this solution, and a refrigerant content below about 50% is defined as a serious shortage, i.e., "serious lack of refrigerant" in this solution.

[0053] S4. After the air conditioner continues to run for d time, it is determined whether △T3>K3 is established. If so, it is determined that the abnormality of the refrigeration system is a circuit blockage. If not, it is determined that the abnormality of the refrigeration system is a serious lack of refrigerant.

[0054] In this step, after the air conditioner continues to run for d time (preferably 10 to 20 seconds), the difference △T3 between the compressor motor winding temperature and the compressor exhaust temperature of the air conditioner is compared with the third preset threshold value K3 to determine whether the circuit is blocked or the refrigerant is seriously missing.

[0055] Since the refrigerant cannot flow effectively in the case of circuit blockage, the temperature of the internal winding of the compressor will continue to rise, and the detection distortion of the temperature at the compressor exhaust port is low. Therefore, there will be a large difference between the compressor motor winding temperature and the compressor exhaust temperature △T3. In the case of severe refrigerant deficiency, the exhaust temperature is relatively high, and the corresponding △T3 will be relatively small. Therefore, by setting a larger third preset threshold K3, it is possible to distinguish whether the system abnormality is circuit blockage or severe refrigerant deficiency, so as to achieve accurate distinction. K3 is preferably 10-11°C.

[0056] It should be noted that the compressor motor winding temperature can be detected by using the estimated value of the compressor motor winding temperature, so that the motor winding temperature can be estimated without increasing the hardware cost or changing the structure. The specific estimation method can be found in the two patents ZL201910249866.9 and ZL201610808947.4, which will not be repeated here.

[0057] If it is determined that the system abnormality is a circuit blockage, for the flammable refrigerant air-conditioning system, there is a possibility that the internal temperature of the compressor will rise after the blockage and the exhaust temperature cannot reach the protection level, eventually causing combustion and explosion. This is a high-risk risk, so it is necessary to immediately shut down for protection, and upload the system circuit blockage system abnormality to the cloud to remind after-sales personnel to come to the door for timely repair and processing.

[0058] If it is determined that the system abnormality is a severe shortage of refrigerant, there will be poor evaporation effect and a risk of high temperature damaging the compressor. Shutdown protection is also required, and the severe refrigerant shortage abnormality should be uploaded to the cloud server to remind after-sales personnel to come to the site to replenish the refrigerant in time.

[0059] S5, after the air conditioner continues to run for d time, determine whether △T1<K2 and △T2<K2 are established, if so, it is determined that the refrigerant is insufficient, otherwise, it is determined that the air conditioner refrigeration system is in a normal state;

[0060] In this step, after the air conditioner continues to run for d time (preferably 10 to 20 seconds), the temperature difference △T1 between the indoor temperature and the inner coil temperature, and the temperature difference △T2 between the outer coil temperature and the outdoor temperature are compared with the second preset threshold value K2 to determine whether there is a shortage of refrigerant.

[0061] In the case of insufficient refrigerant, there is a certain degree of poor evaporation effect and high evaporation temperature. Although the temperature difference △T1 between the indoor temperature and the inner coil temperature is greater than the preset smaller threshold value K1, it will be less than a relatively higher threshold value, and there is a lack of a certain degree of condensation superheat. Therefore, although the difference △T2 between the outdoor coil temperature and the outdoor temperature is greater than the preset smaller threshold value K1, it will be less than a relatively higher threshold value. Therefore, a threshold value K2 that is relatively larger than K1 can be set to achieve judgment, and K2 is preferably 5 to 8°C.

[0062] That is, when ΔT1 and ΔT2 are equal to or greater than K1 and less than K2, it is determined that there is a general refrigerant shortage.

[0063] Since the air conditioner itself has pipe joints, valve seals, etc., as the use cycle is extended and the seals are aged, there will be a certain amount of leakage, so general refrigerant shortage is more common. The refrigerant can operate normally when it is above 70%, but the effect will be appropriately reduced. Therefore, for the abnormal state of general refrigerant shortage, the air conditioner continues to operate, and the abnormal information of refrigerant shortage is uploaded to the cloud server for record backup, reminding after-sales personnel to choose an opportunity to visit the site to check for leaks and replenish refrigerant.

[0064] Based on the above embodiments, accurate positioning of abnormal conditions of the refrigeration system is achieved, so that different protection measures can be adopted for different abnormal conditions, the safety of air-conditioning operation can be improved, and effective guidance can be provided for after-sales service, thereby improving maintenance efficiency and reducing maintenance costs.

[0065] In order to demonstrate the effectiveness of the judgment logic of the solution of the present invention, we obtained key data through a large number of simulation experiments for demonstration. Some experimental cases are listed as follows:

[0066] Experimental Case 1

[0067] In this experiment, under the standard working conditions of GB / T7725, the air conditioner's stop valve was closed before starting the machine with different doses of refrigerant, so as to simulate the situation that the system loop is blocked and the valve is forgotten to be opened after the air conditioner is installed, or the air conditioner has not been used for a period of time, and the throttle valve is blocked by impurities. Through simulation, the air conditioner operating parameter data table obtained by closing the small valve before starting the refrigeration system to simulate the system loop blockage is shown in Table 1, and the corresponding parameter curve is shown in Figure 2 .

[0068] Table 1 Test data of closing small valve before starting refrigeration system (simulating system circuit blockage)

[0069]

[0070] Specifically, when the compressor starts running for a period of time (12 seconds), the maximum power value Power in this period of time can be recorded. max 1018W (see Table 1), and then the power drops sharply (see Figure 2 ), and then continue to run for b time (48S), that is, 60S after startup, it can trigger one of the conditions of refrigeration system circuit blockage or severe refrigerant shortage. current ≤Power max *K0, here K0 is selected as 0.85, that is, 334≤1018*0.85, which meets the judgment condition.

[0071] Continue running for 180 seconds, that is, 240 seconds after startup, the difference between △T1 and △T2 is less than 3.5℃, meeting the second system judgment condition △T1<K1&△T2<K1 (K1 is set to 3.5℃).

[0072] Continue running for 20 seconds, that is, 260 seconds after starting, the difference △T3 between the winding temperature and the exhaust temperature T calculated based on T is 18°C, which is greater than K3 (K3 is set to 11°C).

[0073] Therefore, the above three levels of judgment conditions for circuit blockage are all met, and the system abnormality can be accurately judged to be circuit blockage.

[0074] Experimental Case 2

[0075] In order to demonstrate the power performance characteristics of severe refrigerant loss and circuit blockage at the moment of startup, this experiment was carried out with 50% and 60% normal refrigerant startup and operation respectively. The parameter data of the startup operation are detailed in Table 2 and Table 3, and the corresponding operating parameter curves are shown in Figure 3 and Figure 4 .

[0076] Table 2 Normal startup and operation data table under 50% refrigerant state

[0077]

[0078] Table 3 Normal startup and operation data table under 60% refrigerant state

[0079]

[0080] From Table 2 and Table 3 above, it can be seen that: at 60% refrigerant, the power starts and runs smoothly, and the exhaust and winding temperatures are basically normal. At 50% refrigerant, the power reaches its peak within 23 seconds, and then drops sharply by more than 20%, which is basically similar to circuit blockage. Figure 3 The 50% start-up operation curve in the attached Figure 2 By comparing the blocked start-up operation curves in the figure, it can be seen that the power trends in the two operation curves are similar. This is also one of the factors that easily confuse the two types of system abnormalities in the existing technology. Combined with the similarity of the temperature difference between the inner disk and the inner ring, and the outer disk and the outer ring, it is even easier to confuse. Therefore, it is necessary to use T to calculate the difference between the winding and exhaust temperature to distinguish between circuit blockage and severe lack of refrigerant.

[0081] Experimental case 3

[0082] In order to demonstrate the differentiated performance of normal startup operation data under different refrigerant dosages and blocked startup operation data under different refrigerant dosages, normal startup operation and blocked startup operation were carried out under different refrigerant dosages in this experiment. The obtained parameter tables are shown in Tables 4 and 5 respectively.

[0083] Table 4 Normal startup and operation parameters under different refrigerant dosage conditions

[0084]

[0085] Table 5 Blockage start-up operation parameters under different refrigerant dosage conditions

[0086]

[0087] It can be seen from Table 4 that for normal startup, under normal conditions where the refrigerant dosage is greater than 70%, the temperature difference between the indoor temperature and the inner coil temperature, △T1, and the difference between the outdoor coil temperature and the outdoor temperature, △T2, are both greater than K1 (3.5°C) and K2 (8°C), and when the refrigerant dosage is greater than 50% and less than or equal to 70%, △T1 and △T2 are greater than K1 (3.5°C) and less than K2 (8°C), and the refrigerant dosage is generally insufficient. When the refrigerant dosage is less than 50%, △T1 and △T2 are both less than K1 (3.5°C), and the refrigerant dosage is seriously insufficient.

[0088] It can be seen from Table 5 that for blocked start, not only are △T1 and △T2 both smaller than K1 (3.5°C), but also the difference △T3 between the compressor motor winding temperature and the compressor exhaust temperature is larger than K3 (11°C).

[0089] Therefore, the data in Tables 4 and 5 can demonstrate that the judgment logic of this solution for circuit blockage, severe lack of refrigerant, and insufficient refrigerant is effective and accurate.

[0090] It should be noted that in the above experiments, PT platinum resistors were arranged on the motor windings inside the compressor to measure the motor winding temperature. It can also be seen from the data in Tables 1 to 5 that the deviation between the motor winding temperature obtained by the estimated method and the measured winding temperature is small. Therefore, when implementing the scheme of the present invention, the estimated motor winding temperature can be directly used as the winding temperature, which is applicable under various system abnormal conditions.

[0091] Finally, it should be noted that the above embodiments are only preferred implementations and are not intended to limit the present invention. It should be pointed out that for those skilled in the art, several modifications, equivalent replacements, improvements, etc. can be made without departing from the scope of the present invention and the scope of protection of the claims, and all of these should be included in the protection scope of the present invention.

Claims

1. A method for identifying the state of an air conditioning refrigeration system, characterized in that: The following steps are involved: S1. When the air conditioner is turned on and running in cooling or dehumidification mode for the first time, record the maximum power value of the air conditioner compressor within the first time; S2, after the air conditioner continues to run for the second time, preliminarily determine whether there is an abnormal state of the refrigeration system according to the current power of the air conditioner compressor and the maximum power value in the first time, if so, proceed to step S3, otherwise, exit the determination process; S3, after the air conditioner continues to run for a third time, selecting to enter a circuit blockage and severe refrigerant shortage judgment process or a refrigerant shortage judgment process according to the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature; If the judgment process of circuit blockage and severe lack of refrigerant is entered, the process proceeds to step S4; if the judgment process of insufficient refrigerant is entered, the process proceeds to step S5; S4, after the air conditioner continues to run for a fourth time, judging whether the abnormality of the refrigeration system is a circuit blockage or a serious lack of refrigerant based on the difference between the compressor motor winding temperature and the compressor exhaust temperature of the air conditioner; S5. After the air conditioner continues to operate for a fourth time, determine whether there is a shortage of refrigerant based on the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature.

2. The method for identifying the state of an air conditioning and refrigeration system according to claim 1, characterized in that: In step S2, a preliminary determination is made as to whether there is an abnormal state of the refrigeration system according to the current power of the air conditioner compressor and the maximum power value within the first time, including: JudgmentPower current ≤Power max *Whether K0 is established, if established, it is preliminarily determined that there is an abnormal state of the refrigeration system, if not established, it is determined that there is no abnormal state of the refrigeration system; among them, Power current is the current power of the air conditioner compressor, Power max is the maximum power value of the air conditioner compressor in the first time, and K0 is the preset coefficient.

3. The method for identifying the state of an air conditioning and refrigeration system according to claim 2, characterized in that: In step S3, according to the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature, a circuit blockage and severe refrigerant shortage judgment process or a refrigerant shortage judgment process is selected, including: Determine whether △T1<K1 and △T2<K1 are established. If so, enter the judgment process of circuit blockage and severe lack of refrigerant. If not, enter the judgment process of insufficient refrigerant; wherein △T1 is the temperature difference between the indoor temperature and the inner coil temperature, △T2 is the temperature difference between the outer coil temperature and the outdoor temperature, and K1 is the first preset threshold.

4. The method for identifying the state of an air conditioning and refrigeration system according to claim 3, characterized in that: In step S4, judging whether the abnormality of the refrigeration system is a circuit blockage or a serious lack of refrigerant according to the difference between the compressor motor winding temperature and the compressor exhaust temperature of the air conditioner includes: Determine whether △T3>K3 is established. If so, determine that the abnormality of the refrigeration system is a circuit blockage. If not, determine that the abnormality of the refrigeration system is a serious lack of refrigerant. Among them, △T3 is the difference between the compressor motor winding temperature and the compressor exhaust temperature of the air conditioner, and K3 is the third preset threshold.

5. The method for identifying the state of an air conditioning and refrigeration system according to claim 4, characterized in that: The compressor motor winding temperature of the air conditioner adopts the estimated value of the compressor motor winding temperature.

6. The method for identifying the state of an air conditioning and refrigeration system according to claim 5, characterized in that: In step S5, judging whether there is insufficient refrigerant according to the difference between the indoor temperature and the inner coil temperature, and the difference between the outer coil temperature and the outdoor temperature includes: Determine whether △T1<K2 and △T2<K2 are established. If so, it is determined that the refrigerant is insufficient. Otherwise, it is determined that the air-conditioning refrigeration system is in normal state; wherein △T1 is the temperature difference between the indoor temperature and the inner coil temperature, △T2 is the temperature difference between the outer coil temperature and the outdoor temperature, and K2 is the second preset threshold.

7. The method for identifying the state of an air conditioning and refrigeration system according to claim 6, characterized in that: The first time is 30 to 60 seconds; the second time is 30 to 60 seconds; the third time is 180 to 240 seconds; the fourth time is 10 to 20 seconds; the value range of K0 is 0.85 to 0.65; The value of K1 is 3.5℃; the value of K2 is 5~8℃; the value of K3 is 10~11℃.

8. The method for identifying the state of an air conditioning and refrigeration system according to any one of claims 1 to 7, characterized in that: Step S4 also includes: if it is determined that the refrigeration system abnormality is a circuit blockage, the system is immediately shut down for protection, and the circuit blockage abnormality is uploaded to the cloud server to remind after-sales personnel to come to the door for repair in time; if it is determined that the refrigeration system abnormality is a serious lack of refrigerant, the system is shut down for protection, and the serious lack of refrigerant is uploaded to the cloud server to remind after-sales personnel to come to the door to replenish refrigerant in time; Step S5 also includes: if it is determined that there is a refrigerant shortage abnormality, the air conditioner continues to operate, and the refrigerant shortage abnormality information is uploaded to the cloud server for record backup, reminding after-sales personnel to choose an opportunity to visit the site to check for leaks and replenish refrigerant.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, an air-conditioning and refrigeration system state identification method as described in any one of claims 1 to 7 is implemented.

10. An air conditioning device, comprising a processor and a memory, wherein a computer program is stored in the memory, characterized in that: The processor implements the air-conditioning and refrigeration system state identification method as described in any one of claims 1 to 7 by executing the computer program.

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