A refrigerant state diagnosis method, a computer readable storage medium, and a refrigerator

Abstract

This invention discloses a refrigerant condition diagnosis method, a computer-readable storage medium, and a refrigerator. The refrigerant condition diagnosis method includes: detecting the temperature and current parameters of the compressor during operation; calculating the actual cooling rate and average operating current of the compressor based on the temperature and current parameters; comparing the actual cooling rate with the theoretical cooling rate to obtain a cooling rate deviation value; comparing the average operating current with a standard operating current to obtain an operating current deviation value; and determining the refrigerant condition based on the cooling rate deviation value and the operating current deviation value. Compared with existing technologies, this invention determines the refrigerant condition based on the actual cooling rate rather than a single temperature value, which avoids misjudgments caused by changes in ambient temperature. Furthermore, this invention performs bidirectional diagnosis based on the cooling rate deviation value and the operating current deviation value, enabling accurate differentiation of the refrigerant condition and providing specific guidance for after-sales maintenance.

Description

Technical Field

[0001] This invention relates to the field of refrigeration, and in particular to a refrigerant status diagnosis method, a computer-readable storage medium, and a refrigerator. Background Technology

[0002] As a core household appliance, the refrigerator's refrigeration system directly impacts food preservation and energy efficiency. Refrigerant is the working fluid in the refrigeration cycle, and the accuracy of its injection quantity is crucial. Current technologies for detecting refrigerant status have the following significant shortcomings:

[0003] 1. Reliance on expensive hardware: Currently, refrigerant status detection mostly uses electronic pressure sensors or ultrasonic flow meters to directly measure pressure or flow. Electronic pressure sensors or ultrasonic flow meters are expensive, complex to install (requiring welding of pipes), and difficult to popularize in refrigerators, usually only used in after-sales maintenance.

[0004] 2. High false alarm rate of single parameter: Some refrigerant status detection solutions only judge the refrigerant status based on return gas temperature or running time, which is easily affected by changes in ambient temperature and has a high false alarm rate.

[0005] 3. Inability to distinguish fault types: Both refrigerant leakage (low pressure) and refrigerant excess (high pressure) will lead to a decrease in the heat exchange efficiency of the refrigeration system, manifested as "slow cooling" and "long running time". Current solutions for detecting refrigerant status cannot distinguish between these two diametrically opposed physical states, resulting in users only receiving a vague "system abnormality", which cannot provide specific repair guidance for subsequent maintenance.

[0006] Therefore, how to design a refrigerant status diagnosis method, a computer-readable storage medium, and a refrigerator that can overcome the shortcomings of existing technologies is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0007] To address the problem that existing technologies, which rely on a single parameter to determine the refrigerant status, are easily affected by changes in ambient temperature, this invention proposes a refrigerant status diagnosis method, a computer-readable storage medium, and a refrigerator.

[0008] The technical solution of the present invention is to propose a refrigerant state diagnosis method, including: detecting the temperature parameters and current parameters of the compressor during compressor operation;

[0009] The actual cooling rate and average operating current of the compressor are calculated based on the temperature parameters and the current parameters. The actual cooling rate is compared with the theoretical cooling rate to obtain the cooling rate deviation value, and the average operating current is compared with the standard operating current to obtain the operating current deviation value.

[0010] The refrigerant status is determined based on the deviation value of the cooling rate and the deviation value of the operating current.

[0011] In the above-mentioned technical solution, this invention improves the method for determining the refrigerant status. Instead of relying solely on a single temperature parameter (return gas temperature), it adjusts the method to determine the status based on the actual cooling rate. This avoids false alarms caused by changes in ambient temperature and enhances anti-interference capabilities. Furthermore, this invention combines the actual cooling rate with the average operating current to calculate the cooling rate deviation and operating current deviation values ​​respectively. Through bidirectional diagnostics, it can accurately distinguish between refrigerant leakage (or insufficient refrigerant injection) and excessive refrigerant injection, providing specific guidance for after-sales maintenance. Moreover, in the above-mentioned determination process, this invention only requires the collection of temperature and current parameters. It can utilize only a common temperature sensor and existing current detection circuit, eliminating the need for expensive pressure sensors or ultrasonic flow meters, significantly reducing design costs.

[0012] Furthermore, determining the refrigerant state based on the cooling rate deviation value and the operating current deviation value includes:

[0013] A two-dimensional coordinate system is constructed with the cooling rate deviation value and the operating current deviation value as the abscissa and ordinate, and at least one cooling rate deviation threshold and at least one operating current deviation threshold are set to divide the two-dimensional coordinate system into multiple intervals.

[0014] The refrigerant state is determined based on the range in which the cooling rate deviation value and the operating current deviation value fall.

[0015] This invention maps cooling rate deviation and operating current deviation values ​​onto a two-dimensional coordinate system and divides the two-dimensional coordinate system into multiple intervals based on set cooling rate deviation thresholds and operating current deviation thresholds. This allows those skilled in the art to directly determine the refrigerant state based on the intervals where the cooling rate deviation and operating current deviation values ​​are located. Furthermore, the multiple intervals divided by the two-dimensional coordinate system can accurately distinguish the factors that cause a decrease in the cooling rate of the refrigeration system, going beyond simple refrigerant state detection. It can provide a precise guide for determining the cause of a fault when the cooling rate of the refrigeration system decreases, providing a specific direction for after-sales maintenance.

[0016] Furthermore, the cooling rate deviation threshold is set to two values, including a first threshold less than 1 and a second threshold greater than 1.

[0017] The operating current deviation threshold is set in two ways, including a third threshold less than 1 and a fourth threshold greater than 1.

[0018] The first threshold, the second threshold, the third threshold, and the fourth threshold divide the two-dimensional coordinate system into at least seven intervals;

[0019] Wherein, when the cooling rate deviation value is less than the first threshold and the operating current deviation value is less than the third threshold, it is divided into the first interval;

[0020] When the cooling rate deviation is less than the first threshold and the operating current deviation is between the third threshold and the fourth threshold, it is divided into the second interval;

[0021] When the cooling rate deviation is less than the first threshold and the operating current deviation is greater than the fourth threshold, it is divided into the third interval;

[0022] When the cooling rate deviation is between the first threshold and the second threshold, and the operating current deviation is less than the third threshold, it is divided into the fourth interval;

[0023] When the cooling rate deviation is between the first threshold and the second threshold, and the operating current deviation is between the third threshold and the fourth threshold, it is divided into the fifth interval;

[0024] When the cooling rate deviation is between the first threshold and the second threshold, and the operating current deviation is greater than the fourth threshold, it is divided into the sixth interval;

[0025] When the cooling rate deviation value is greater than the second threshold, it is divided into the seventh interval.

[0026] This invention divides a two-dimensional coordinate system into at least seven intervals by setting a first threshold less than 1 and a second threshold greater than 1 for the cooling rate deviation threshold, and combining this with a third threshold less than 1 and a fourth threshold greater than 1 for the operating current deviation threshold. This results in different cooling rate deviation values ​​and operating current deviation values ​​corresponding to different intervals, thereby assigning different refrigerant states to different intervals. Those skilled in the art can directly determine the refrigerant state based on the interval in which the cooling rate deviation value and operating current deviation value are located, making the entire determination process simpler and more intuitive.

[0027] Furthermore, when the cooling rate deviation value and the operating current deviation value are within the first range, the refrigerant status is determined to be either refrigerant leakage or insufficient refrigerant injection.

[0028] When the deviation values ​​of cooling rate and operating current are in the first range, it indicates that the actual cooling rate is reduced and the average operating current is reduced. By comprehensively considering the two factors of reduced actual cooling rate and reduced average operating current, this invention can determine that the reason for the reduced cooling rate in the refrigeration system is that the refrigerant is reduced, resulting in a reduction in the effective heat exchange area of ​​the evaporator. At the same time, the suction pressure of the refrigeration system is reduced, which reduces the load on the compressor. Based on the above factors, this invention can accurately determine that the refrigerant status is either refrigerant leakage or insufficient refrigerant injection.

[0029] Furthermore, when the cooling rate deviation value and the operating current deviation value are within the second range, the refrigerant state is determined to be normal, and the actual cooling rate of the refrigeration system is a normal fluctuation caused by the increase in load.

[0030] When the deviation values ​​of cooling rate and operating current are in the second range, it indicates that the actual cooling rate has decreased, but the average operating current is still within the normal range. By combining the two factors of the actual cooling rate decreasing but the average operating current still being within the normal range, this invention can determine that the refrigeration system is in normal working condition at this time. The reason for the decrease in the actual cooling rate is the normal fluctuation caused by the increase in the load of the refrigeration system.

[0031] Furthermore, when the cooling rate deviation value and the operating current deviation value are in the third range, the refrigerant state is determined to be excessive refrigerant injection.

[0032] When the deviation values ​​of cooling rate and operating current are in the third range, it indicates that the actual cooling rate is decreasing, but the average operating current is increasing. By combining the two factors of decreasing actual cooling rate and increasing average operating current, this invention can determine that the reason for the decrease in actual cooling rate is that too much refrigerant causes liquid accumulation in the condenser and increases the pressure in the condenser. The reason for the increase in average operating current is that the compressor discharge resistance increases sharply. Combining the above factors, this invention can accurately determine that the refrigerant state is that the refrigerant quantity is excessive.

[0033] Furthermore, when the cooling rate deviation value and the operating current deviation value are in the fourth or sixth interval, the refrigerant state is determined to be normal, but the compressor is abnormal or other components in the refrigeration system have failed.

[0034] When the deviation values ​​of cooling rate and operating current are in the fourth or sixth range, this invention can determine that the actual cooling rate of the current refrigeration system is normal, that is, the heat exchange of the evaporator is normal. Combined with the abnormal average operating current, this invention can accurately determine that the cause of the fault in the refrigeration system is either compressor malfunction or failure of other components in the refrigeration system.

[0035] Furthermore, when the cooling rate deviation value and the operating current deviation value are in the fifth range, it is determined that the refrigerant state is normal and the refrigeration system is normal.

[0036] When the cooling rate deviation and the operating current deviation are in the fifth range, the present invention can determine that the actual cooling rate and the average operating current of the refrigeration system are in a normal state based on the range in which the cooling rate deviation and the operating current deviation are located, thereby accurately determining that the refrigerant state is normal.

[0037] Furthermore, when the cooling rate deviation value and the operating current deviation value are in the seventh interval, the refrigeration system is determined to be abnormal, and the abnormal state is at least one of the following: a sudden change in ambient temperature, a sensor failure used to detect the temperature parameter and the current parameter, and a lag in the benchmark model of the theoretical cooling rate.

[0038] When the deviation values ​​of cooling rate and operating current are in the seventh interval, it indicates that the actual cooling rate is increasing and deviating from the theoretical situation. Under this condition, the present invention can determine that the refrigeration system is abnormal and accurately locate the abnormal state as at least one of the following: a sudden change in ambient temperature, a sensor failure used to detect the temperature and current parameters, or a lag in the benchmark model of the theoretical cooling rate.

[0039] Furthermore, the temperature parameter is the return gas temperature of the compressor, and the current parameter is the operating current of the compressor.

[0040] In the above-mentioned judgment process, the present invention only needs to collect temperature and current parameters. It can use only a common temperature sensor and an existing current detection circuit, without the need to use expensive pressure sensors or ultrasonic flow meters, which greatly reduces the design cost.

[0041] Furthermore, the calculation model for the actual cooling rate is: Ks = ΔT / Δt;

[0042] Wherein, Ks is the actual cooling rate, ΔT is the return gas temperature drop value within a preset time, and Δt is the preset time.

[0043] Based on the above technical solution, this invention improves the method for judging the refrigerant status. Instead of judging based on a single temperature parameter (return gas temperature), it is adjusted to judge based on the actual cooling rate, which can avoid false alarms caused by changes in ambient temperature and has stronger anti-interference ability.

[0044] Furthermore, the calculation model for the cooling rate deviation value is: δK=Ks / Ki;

[0045] Wherein, δK is the cooling rate deviation value, Ks is the actual cooling rate, and Ki is the theoretical cooling rate.

[0046] This invention calculates the cooling rate deviation value and combines it with the operating current deviation value to accurately distinguish whether the refrigerant status is due to refrigerant leakage (or insufficient refrigerant injection) or excessive refrigerant injection through bidirectional diagnosis, providing specific guidance for after-sales maintenance.

[0047] Furthermore, the calculation model for the operating current deviation value is: δI=Is / Ii;

[0048] Wherein, δI is the operating current deviation value, Is is the average operating current, and Ii is the standard operating current.

[0049] This invention calculates the operating current deviation value and combines it with the cooling rate deviation value to accurately distinguish whether the refrigerant status is due to refrigerant leakage (or insufficient refrigerant injection) or excessive refrigerant injection through bidirectional diagnosis, providing specific guidance for after-sales maintenance.

[0050] The present invention also proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described refrigerant status diagnosis method.

[0051] The present invention also proposes a refrigerator having the aforementioned computer-readable storage medium.

[0052] Compared with the prior art, the present invention has at least the following beneficial effects:

[0053] The method for determining refrigerant status has been improved. Instead of relying solely on a single temperature parameter (return gas temperature), it now bases the assessment on the actual cooling rate. This avoids false alarms caused by changes in ambient temperature and enhances anti-interference capabilities. Furthermore, this invention combines the actual cooling rate with the average operating current, calculating both the cooling rate deviation and the operating current deviation. Through bidirectional diagnostics, it can accurately distinguish between refrigerant leakage (or insufficient refrigerant) and excessive refrigerant, providing specific guidance for after-sales maintenance. Moreover, this invention only requires temperature and current parameters in the aforementioned assessment process, necessitating the use of a standard temperature sensor and existing current detection circuitry. This eliminates the need for expensive pressure sensors or ultrasonic flow meters, significantly reducing design costs. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating the overall process of the refrigerant condition diagnosis method in this invention.

[0056] Figure 2 This is a flowchart illustrating how the refrigerant state is determined based on the deviation between the cooling rate and the operating current in this invention.

[0057] Figure 3 This is a schematic diagram of the interval division of a two-dimensional coordinate system in one embodiment of the present invention;

[0058] Figure 4 This is a schematic diagram of the interval division of the two-dimensional coordinate system in another embodiment of the present invention;

[0059] Figure 5 This is a schematic diagram of the interval division of the two-dimensional coordinate system in another embodiment of the present invention;

[0060] Figure 6 This is a schematic diagram illustrating the refrigerant state determination based on the range of cooling rate deviation and operating current deviation in this invention.

[0061] Figure 7 This is a schematic diagram illustrating the graded early warning system for different refrigerant states in this invention;

[0062] Figure 8 This is a flowchart illustrating the overall process of refrigerant determination and early warning in a specific embodiment of the present invention. Detailed Implementation

[0063] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0064] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the invention, and does not imply that every embodiment of the invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0065] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0066] The existing technologies for detecting refrigerant status have the following significant drawbacks:

[0067] 1. Reliance on expensive hardware: Currently, refrigerant status detection mostly uses electronic pressure sensors or ultrasonic flow meters to directly measure pressure or flow. Electronic pressure sensors or ultrasonic flow meters are expensive, complex to install (requiring welding of pipes), and difficult to popularize in refrigerators, usually only used in after-sales maintenance.

[0068] 2. High false alarm rate of single parameter: Some refrigerant status detection solutions only judge the refrigerant status based on return gas temperature or running time, which is easily affected by changes in ambient temperature and has a high false alarm rate.

[0069] 3. Inability to distinguish fault types: Both refrigerant leakage (low pressure) and refrigerant excess (high pressure) will lead to a decrease in the heat exchange efficiency of the refrigeration system, manifested as "slow cooling" and "long running time". Current solutions for detecting refrigerant status cannot distinguish between these two diametrically opposed physical states, resulting in users only receiving a vague "system abnormality", which cannot provide specific repair guidance for subsequent maintenance.

[0070] To address the above problems, this invention proposes a refrigerant condition diagnosis method. Please refer to [link / reference]. Figure 1 It includes the following steps: when the compressor is running, detect the compressor's temperature and current parameters;

[0071] The actual cooling rate and average operating current of the compressor are calculated based on temperature and current parameters. The actual cooling rate is compared with the theoretical cooling rate to obtain the cooling rate deviation value, and the average operating current is compared with the standard operating current to obtain the operating current deviation value.

[0072] The refrigerant status is determined by the deviation values ​​of the cooling rate and the operating current.

[0073] Based on the above solution, the present invention can solve the technical defects mentioned above. Regarding the problem of relying on expensive hardware, the refrigerant status diagnosis method proposed in the present invention only needs to detect temperature and current parameters. It can use only ordinary temperature sensors and existing current detection circuits, without the need to use expensive pressure sensors or ultrasonic flow meters, which can greatly reduce design costs.

[0074] To address the issue of high false alarm rate for single parameters, this invention adjusts the original judgment based on a single temperature parameter (return gas temperature) to a judgment based on the actual cooling rate, thereby avoiding false alarms caused by changes in ambient temperature and enhancing anti-interference capabilities.

[0075] To address the problem of not being able to distinguish the type of fault, this invention combines the actual cooling rate with the average operating current to calculate the deviation values ​​of the cooling rate and the operating current, respectively. Through bidirectional diagnosis, it can accurately distinguish whether the refrigerant status is refrigerant leakage (or insufficient refrigerant injection) or excessive refrigerant injection, providing specific direction for after-sales maintenance.

[0076] The above scheme, which determines the refrigerant state based on the deviation between the cooling rate and the operating current, includes:

[0077] A two-dimensional coordinate system is constructed with the cooling rate deviation value and the operating current deviation value as the abscissa and ordinate, and at least one cooling rate deviation threshold and at least one operating current deviation threshold are set to divide the two-dimensional coordinate system into multiple intervals.

[0078] The refrigerant status is determined based on the range of the cooling rate deviation and the operating current deviation.

[0079] In this scheme, the present invention maps the cooling rate deviation value and the operating current deviation value to a two-dimensional coordinate system, and divides the two-dimensional coordinate system into multiple intervals according to the set cooling rate deviation threshold and operating current deviation threshold. This allows those skilled in the art to directly determine the refrigerant state based on the interval in which the cooling rate deviation value and the operating current deviation value are located. In addition, the present invention can also accurately distinguish the factors that cause the cooling rate of the refrigeration system to decrease based on the multiple intervals divided by the two-dimensional coordinate system. It is not limited to simple refrigerant state detection, but can provide a precise guide for judging the cause of the fault when the cooling rate of the refrigeration system decreases, and provide a specific direction for after-sales maintenance.

[0080] Please see Figure 3 In one embodiment of the present invention, both the cooling rate deviation threshold and the operating current deviation threshold are set to one, wherein K1 is the cooling rate deviation threshold and I1 is the operating current deviation threshold. In this embodiment, based on the setting of the cooling rate deviation threshold K1 and the operating current deviation threshold I1, the two-dimensional coordinate system is divided into two intervals, namely interval I and interval II.

[0081] Based on this embodiment, the present invention can be used to determine refrigerant leakage or insufficient refrigerant injection in a refrigeration system. When both the cooling rate deviation value and the operating current deviation value are within the range I, it is determined that there is refrigerant leakage or insufficient refrigerant injection.

[0082] The aforementioned cooling rate deviation threshold K1 can be set to 0.9, and the aforementioned operating current deviation threshold I1 can be set to 0.95.

[0083] Please see Figure 4In another embodiment of the present invention, both the cooling rate deviation threshold and the operating current deviation threshold are set to one, wherein K1 is the cooling rate deviation threshold and I2 is the operating current deviation threshold. In this embodiment, based on the setting of the cooling rate deviation threshold K1 and the operating current deviation threshold I2, the two-dimensional coordinate system is divided into two intervals, namely interval I and interval II.

[0084] Based on this embodiment, the present invention can be used to determine that the refrigerant quantity is excessive in the refrigeration system. When both the cooling rate deviation value and the operating current deviation value are within the range I, it is determined that the refrigerant quantity is excessive.

[0085] The aforementioned cooling rate deviation threshold K1 can be set to 0.9, and the aforementioned operating current deviation threshold I2 can be set to 1.05.

[0086] Please see Figure 5 In another embodiment of the present invention, two cooling rate deviation thresholds are set, including a first threshold K1 less than 1 and a second threshold K2 greater than 1.

[0087] There are two operating current deviation threshold settings, including a third threshold I1 which is less than 1 and a fourth threshold I2 which is greater than 1;

[0088] The first threshold K1, the second threshold K2, the third threshold I1, and the fourth threshold I2 divide the two-dimensional coordinate system into at least seven intervals;

[0089] Among them, when the cooling rate deviation is less than the first threshold K1 and the operating current deviation is less than the third threshold I1, it is divided into the first interval I;

[0090] When the cooling rate deviation is less than the first threshold K1 and the operating current deviation is between the third threshold I1 and the fourth threshold I2, it is divided into the second interval II.

[0091] When the cooling rate deviation is less than the first threshold K1 and the operating current deviation is greater than the fourth threshold I2, it is classified as the third interval III.

[0092] When the cooling rate deviation is between the first threshold K1 and the second threshold K2, and the operating current deviation is less than the third threshold I1, it is divided into the fourth interval IV.

[0093] When the cooling rate deviation is between the first threshold K1 and the second threshold K2, and the operating current deviation is between the third threshold I1 and the fourth threshold I2, it is divided into the fifth interval V;

[0094] When the cooling rate deviation is between the first threshold K1 and the second threshold K2, and the operating current deviation is greater than the fourth threshold I2, it is divided into the sixth interval VI.

[0095] When the cooling rate deviation is greater than the second threshold K2, it is divided into the seventh interval VII.

[0096] Based on this embodiment, the present invention divides the two-dimensional coordinate system into at least seven intervals by setting a first threshold K1 less than 1 and a second threshold K2 greater than 1 for the cooling rate deviation threshold, and combining a third threshold I1 less than 1 and a fourth threshold I2 greater than 1 for the operating current deviation threshold. This makes the cooling rate deviation value and operating current deviation value different for different intervals, thereby allowing different refrigerant states to be divided into different intervals. Those skilled in the art can directly judge the refrigerant state based on the interval where the cooling rate deviation value and operating current deviation value are located, omitting the additional complex calculation process, and can intuitively characterize the refrigerant state of the refrigeration system.

[0097] The first threshold K1 is preferably set to 0.9, the second threshold K2 is preferably set to 1.1, the third threshold I1 is preferably set to 0.95, and the fourth threshold I2 is preferably set to 1.05.

[0098] The following sections explain the refrigerant states corresponding to the intervals in which the cooling rate deviation and operating current deviation values ​​lie:

[0099] 1. When the cooling rate deviation and the operating current deviation are in the first range, the refrigerant condition is determined to be either refrigerant leakage or insufficient refrigerant injection.

[0100] When the deviation values ​​of cooling rate and operating current are in the first range, it indicates that the actual cooling rate is reduced and the average operating current is reduced. By comprehensively considering the two factors of reduced actual cooling rate and reduced average operating current, this invention can determine that the reason for the reduced cooling rate in the refrigeration system is that the refrigerant is reduced, resulting in a reduction in the effective heat exchange area of ​​the evaporator. At the same time, the suction pressure of the refrigeration system is reduced, which reduces the load on the compressor. Based on the above factors, this invention can accurately determine that the refrigerant status is either refrigerant leakage or insufficient refrigerant injection.

[0101] 2. When the deviation values ​​of cooling rate and operating current are in the second range, the refrigerant state is determined to be normal, and the actual cooling rate of the refrigeration system is a normal fluctuation caused by the increase in load.

[0102] When the deviation values ​​of cooling rate and operating current are in the second range, it indicates that the actual cooling rate has decreased, but the average operating current is still within the normal range. By combining the two factors of the actual cooling rate decreasing but the average operating current still being within the normal range, this invention can determine that the refrigeration system is in normal working condition at this time. The reason for the decrease in the actual cooling rate is the normal fluctuation caused by the increase in the load of the refrigeration system.

[0103] 3. When the deviation values ​​of cooling rate and operating current are in the third range, the refrigerant status is determined to be excessive refrigerant injection.

[0104] When the deviation values ​​of cooling rate and operating current are in the third range, it indicates that the actual cooling rate is decreasing, but the average operating current is increasing. By combining the two factors of decreasing actual cooling rate and increasing average operating current, this invention can determine that the reason for the decrease in actual cooling rate is that too much refrigerant causes liquid accumulation in the condenser and increases the pressure in the condenser. The reason for the increase in average operating current is that the compressor discharge resistance increases sharply. Combining the above factors, this invention can accurately determine that the refrigerant state is that the refrigerant quantity is excessive.

[0105] 4. When the deviation values ​​of cooling rate and operating current are in the fourth or sixth range, the refrigerant is determined to be in a normal state, but the compressor is abnormal or other components in the refrigeration system have failed.

[0106] Among these cases, if the deviation values ​​for cooling rate and operating current are in the fourth range, the cooling rate of the refrigeration system is normal, indicating sufficient refrigerant charge and normal evaporator heat exchange. However, the average operating current of the compressor is lower than the normal benchmark. The possible fault in this case is: increased internal leakage due to wear of the compressor piston rings and valves, resulting in a decrease in the compression ratio. Although suction and discharge are smooth (high efficiency), the load torque demand is reduced, leading to a decrease in the average operating current. This primarily indicates a compressor fault, prompting users and maintenance personnel to inspect and repair the compressor.

[0107] If the deviation values ​​of cooling rate and operating current are in the fourth or sixth range, the cooling rate of the refrigeration system is normal, indicating that the refrigerant charge is sufficient and the evaporator heat exchange is normal. However, the average operating current of the compressor is higher than the normal reference, indicating that the compressor is operating under heavy load and the average operating current exceeds the rated value. The possible faults at this time are: ① Mechanical friction / seizing: insufficient oil in the compressor bearings, deformation of the connecting rod, or rotor failure, resulting in a sharp increase in mechanical resistance, requiring the motor to output more torque to maintain operation;

[0108] ② Condenser blockage: The condenser surface is heavily dusty but not completely blocked. The high pressure rises slightly, but it has not yet affected the evaporation efficiency. At this time, the main manifestation is an increase in motor load.

[0109] ③ Motor insulation aging: Short circuit between winding turns may manifest as an abnormal increase in current. If this condition is detected, the refrigeration system needs to provide feedback to prompt immediate repair of the condenser or compressor to avoid dangerous situations.

[0110] 5. When the deviation values ​​of cooling rate and operating current are in the fifth range, the refrigerant is considered to be in a normal state, and the refrigeration system is normal.

[0111] When the cooling rate deviation and the operating current deviation are in the fifth range, the present invention can determine that the actual cooling rate and the average operating current of the refrigeration system are in a normal state based on the range in which the cooling rate deviation and the operating current deviation are located, thereby accurately determining that the refrigerant state is normal.

[0112] 6. When the deviation values ​​of cooling rate and operating current are in the seventh range, the refrigeration system is determined to be abnormal. The abnormal state is at least one of the following: a sudden change in ambient temperature, a sensor failure used to detect temperature and current parameters, or a lag in the benchmark model of the theoretical cooling rate.

[0113] Within this seventh interval, it indicates that the actual cooling rate of the refrigeration system is higher than the theoretical cooling rate. This operating condition does not exist in the theoretical operation of the refrigeration system. If the deviation value of the cooling rate and the deviation value of the operating current are detected to be within the seventh interval, it may be that a certain data is abnormal. Possible causes of failure at this time include: ① Sudden change in ambient temperature: The ambient temperature is extremely low in winter, resulting in a large initial temperature difference and an artificially high calculated slope.

[0114] ② Temperature sensor malfunction: Poor contact of the temperature sensor leads to incorrect readings;

[0115] ③ Lagging benchmark model: After many years of use, the performance of the refrigeration system naturally degrades, but the benchmark library has not been updated;

[0116] In this case, the refrigeration system can trigger a self-learning mechanism to dynamically correct the cooling rate deviation value δK and the operating current deviation value δI using the current data, and then learn on its own. Since the reference data at the factory is measured in the laboratory, the ambient temperature during actual use by the user is uncontrollable. Therefore, when δK>K2, it is considered that the environment does not match the reference.

[0117] At this point, we can first eliminate load interference: exclude the data from the first 3 startups after a large amount of hot food has just been put in;

[0118] Then, eliminate frequent start-stop cycles: exclude short-cycle operation data caused by thermostat malfunction;

[0119] Finally, only data with operating current deviation δI within the normal range and cooling rate deviation δK stable are selected as valid samples.

[0120] The new benchmark is calculated using the system formula: K(t+1) = aK(t) + (1-a)Kmt;

[0121] Kt represents the current standard cooling slope baseline value stored in the system memory at time t;

[0122] Kmt represents the measured cooling slope obtained in real time by the sensor at time t;

[0123] 'a' represents the smoothing coefficient, which ranges from 0 to 1. In this embodiment, a value of 0.9 is recommended.

[0124] K(t+1) represents the updated new generation standard cooling slope benchmark value;

[0125] This step allows the baseline model to be updated, thereby obtaining the theoretical cooling rate and standard operating current adapted to the current operating conditions. Then, by re-performing the refrigerant status diagnosis, an accurate judgment result on the refrigerant status can be obtained.

[0126] Please see Figure 6 This is a schematic diagram of the refrigerant status judgment based on the interval of the cooling rate deviation value and the operating current deviation value in the present invention. It first determines the interval of the cooling rate deviation value and the operating current deviation value. If it is the first interval, the refrigerant status is determined to be refrigerant leakage or insufficient refrigerant injection.

[0127] If it is the second interval, the refrigerant state is determined to be normal, and the decrease in the actual cooling rate of the refrigeration system is a normal fluctuation caused by the increase in load.

[0128] If it is the third zone, the refrigerant status is determined to be excessive refrigerant injection;

[0129] If it is the fourth or sixth zone, the refrigerant status is determined to be normal, but the compressor is abnormal or other components in the refrigeration system have failed.

[0130] If it is the fifth zone, then the refrigerant status is determined to be normal, and the refrigeration system is normal.

[0131] If it is the seventh interval, the refrigeration system is determined to be abnormal, and the abnormal state is at least one of the following: a sudden change in ambient temperature, a sensor failure used to detect temperature and current parameters, or a lag in the benchmark model of the theoretical cooling rate.

[0132] In the refrigerant condition diagnosis method proposed in this invention, the temperature parameter is the return gas temperature of the compressor, and the current parameter is the operating current of the compressor.

[0133] In the above-mentioned judgment process, the present invention only needs to collect temperature and current parameters. It can use only a common temperature sensor and an existing current detection circuit, without the need to use expensive pressure sensors or ultrasonic flow meters, which greatly reduces the design cost.

[0134] Furthermore, the calculation model for the actual cooling rate is: Ks = ΔT / Δt;

[0135] Where Ks is the actual cooling rate, ΔT is the decrease in return gas temperature within the preset time, and Δt is the preset time.

[0136] Based on the above technical solution, this invention improves the method for judging the refrigerant status. Instead of judging based on a single temperature parameter (return gas temperature), it is adjusted to judge based on the actual cooling rate, which can avoid false alarms caused by changes in ambient temperature and has stronger anti-interference ability.

[0137] Furthermore, the average operating current can be determined by the power consumption and operating voltage of the refrigeration system over a certain period of time, or by averaging the values ​​of multiple operating current measurements.

[0138] Furthermore, the calculation model for the cooling rate deviation is: δK=Ks / Ki;

[0139] Where δK is the cooling rate deviation, Ks is the actual cooling rate, and Ki is the theoretical cooling rate.

[0140] This invention calculates the cooling rate deviation value and combines it with the operating current deviation value to accurately distinguish whether the refrigerant status is due to refrigerant leakage (or insufficient refrigerant injection) or excessive refrigerant injection through bidirectional diagnosis, providing specific guidance for after-sales maintenance.

[0141] Furthermore, the calculation model for the operating current deviation is: δI=Is / Ii;

[0142] Where δI is the operating current deviation value, Is is the average operating current, and Ii is the standard operating current.

[0143] This invention calculates the operating current deviation value and combines it with the cooling rate deviation value to accurately distinguish whether the refrigerant status is due to refrigerant leakage (or insufficient refrigerant injection) or excessive refrigerant injection through bidirectional diagnosis, providing specific guidance for after-sales maintenance.

[0144] After implementing the above-described solution, this invention can accurately determine the refrigerant status and provide graded early warnings based on the diagnostic results. Please refer to [link / reference needed]. Figure 7 In this invention, the diagnostic results of the refrigerant status are divided into three levels:

[0145] Level 1: Minor refrigerant loss, indicating a need to check the sealing strip; This situation mainly occurs when the deviation values ​​of cooling rate and operating current are in the second range. At this time, the actual cooling rate of the refrigeration system decreases due to normal fluctuations caused by increased load, or it may be due to a slight leak in the sealing strip, requiring a check of the sealing strip.

[0146] Level 2: Refrigerant is severely insufficient, immediate repair is recommended; This situation mainly applies when the deviation values ​​of cooling rate and operating current are in the first range. At this time, the refrigerant condition is determined to be either refrigerant leakage or insufficient refrigerant injection, and immediate repair is required.

[0147] Level 3: Risk of excessive refrigerant, warning against liquid slugging that could damage the compressor; this situation mainly applies when the deviation values ​​of cooling rate and operating current are in the third range, at which point the refrigerant status is determined to be excessive refrigerant injection.

[0148] By classifying the above diagnostic results, this invention provides different early warning strategies based on different refrigerant states, further ensuring the reliability of the refrigeration system.

[0149] Please see Figure 8 In a specific embodiment of the present invention, the above-mentioned refrigerant status diagnosis method includes the following steps:

[0150] 1. Data acquisition and benchmark establishment; This includes installing a temperature sensor on the compressor return gas line to collect the return gas temperature, detecting the main control board circuit, collecting the compressor's operating current in real time, and then obtaining the theoretical cooling rate and standard operating current based on the benchmark model library of the refrigeration system under standard operating conditions.

[0151] 2. Dynamic characteristic calculation; that is, the steps of calculating the actual cooling rate and average operating current;

[0152] 3. Deviation normalization and feature mapping; that is, the steps of calculating the deviation value of cooling rate by comparing actual cooling rate with theoretical cooling rate, and calculating the deviation value of operating current by comparing average operating current with standard operating current, and constructing a two-dimensional coordinate system.

[0153] 4. Two-way logic judgment; that is, the steps of diagnosing the refrigerant state by using the range of the cooling rate deviation value and the operating current deviation value.

[0154] 5. Early warning output; that is, the step of issuing graded early warnings based on the diagnostic results.

[0155] Based on the above-mentioned solution, this invention improves the method for determining the refrigerant status. Instead of relying solely on a single temperature parameter (return gas temperature), it adjusts the method to judge based on the actual cooling rate. This avoids false alarms caused by changes in ambient temperature and enhances anti-interference capabilities. Furthermore, this invention combines the actual cooling rate with the average operating current, calculating the cooling rate deviation and operating current deviation values ​​respectively. Through bidirectional diagnostics, it can accurately distinguish between refrigerant leakage (or insufficient refrigerant injection) and excessive refrigerant injection, providing specific guidance for after-sales maintenance. Moreover, in the above-mentioned judgment process, this invention only requires the collection of temperature and current parameters, using only a common temperature sensor and existing current detection circuit, eliminating the need for expensive pressure sensors or ultrasonic flow meters, significantly reducing design costs.

[0156] The present invention also proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described refrigerant status diagnosis method.

[0157] The present invention also proposes a refrigerator having the aforementioned computer-readable storage medium. This refrigerator can be used for refrigerant diagnostics in currently required energy-saving refrigerators, further ensuring the energy-saving effect of the refrigerator while guaranteeing its operational efficiency.

[0158] It should be noted that the terminology used above is for describing specific embodiments only and is not intended to limit the exemplary embodiments of the present invention. When the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. The order of execution of actions, steps, etc., in the apparatus and methods described in the specification and drawings can be implemented in any order unless a specific order is expressly specified, and as long as the output of the preceding process is not used in the subsequent process. Similar sequential terms used for ease of description do not imply that such an order must be followed.

[0159] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as constraints. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0160] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A refrigerant state diagnosis method characterized by comprising: include: During compressor operation, the temperature and current parameters of the compressor are detected; The actual cooling rate and average operating current of the compressor are calculated based on the temperature parameters and the current parameters. The actual cooling rate is compared with the theoretical cooling rate to obtain the cooling rate deviation value, and the average operating current is compared with the standard operating current to obtain the operating current deviation value. The refrigerant status is determined based on the deviation value of the cooling rate and the deviation value of the operating current.

2. The refrigerant state diagnosis method according to claim 1, characterized by Determining the refrigerant state based on the cooling rate deviation and the operating current deviation includes: A two-dimensional coordinate system is constructed with the cooling rate deviation value and the operating current deviation value as the abscissa and ordinate, and at least one cooling rate deviation threshold and at least one operating current deviation threshold are set to divide the two-dimensional coordinate system into multiple intervals. The refrigerant state is determined based on the range in which the cooling rate deviation value and the operating current deviation value fall.

3. The refrigerant state diagnosis method according to claim 2, characterized by The cooling rate deviation threshold is set to two, including a first threshold less than 1 and a second threshold greater than 1; The operating current deviation threshold is set in two ways, including a third threshold less than 1 and a fourth threshold greater than 1. The first threshold, the second threshold, the third threshold, and the fourth threshold divide the two-dimensional coordinate system into at least seven intervals; Wherein, when the cooling rate deviation value is less than the first threshold and the operating current deviation value is less than the third threshold, it is divided into the first interval; When the cooling rate deviation is less than the first threshold and the operating current deviation is between the third threshold and the fourth threshold, it is divided into the second interval; When the cooling rate deviation is less than the first threshold and the operating current deviation is greater than the fourth threshold, it is divided into the third interval; When the cooling rate deviation is between the first threshold and the second threshold, and the operating current deviation is less than the third threshold, it is divided into the fourth interval; When the cooling rate deviation is between the first threshold and the second threshold, and the operating current deviation is between the third threshold and the fourth threshold, it is divided into the fifth interval; When the cooling rate deviation is between the first threshold and the second threshold, and the operating current deviation is greater than the fourth threshold, it is divided into the sixth interval; When the cooling rate deviation value is greater than the second threshold, it is divided into the seventh interval.

4. The refrigerant state diagnosis method according to claim 3, characterized by When the cooling rate deviation value and the operating current deviation value are within the first range, the refrigerant status is determined to be either refrigerant leakage or insufficient refrigerant injection.

5. The refrigerant state diagnosis method according to claim 3, characterized by When the deviation value of the cooling rate and the deviation value of the operating current are in the second range, the refrigerant state is determined to be normal, and the decrease in the actual cooling rate of the refrigeration system is a normal fluctuation caused by the increase in load.

6. The refrigerant state diagnosis method according to claim 3, characterized by When the cooling rate deviation and the operating current deviation are in the third range, the refrigerant state is determined to be excessive refrigerant injection.

7. The refrigerant state diagnosis method according to claim 3, characterized by When the cooling rate deviation value and the operating current deviation value are in the fourth or sixth interval, the refrigerant state is determined to be normal, but the compressor is abnormal or other components in the refrigeration system are malfunctioning.

8. The refrigerant state diagnosis method according to claim 3, characterized by When the cooling rate deviation and the operating current deviation are in the fifth range, the refrigerant is determined to be in a normal state, and the refrigeration system is normal.

9. The refrigerant state diagnosis method according to claim 3, characterized by When the deviation value of the cooling rate and the deviation value of the operating current are in the seventh interval, the refrigeration system is determined to be abnormal, and the abnormal state is at least one of the following: a sudden change in ambient temperature, a sensor failure used to detect the temperature parameter and the current parameter, and a lag in the benchmark model of the theoretical cooling rate.

10. The refrigerant state diagnosis method according to claim 1, characterized by The temperature parameter is the return gas temperature of the compressor, and the current parameter is the operating current of the compressor.

11. The refrigerant condition diagnosis method according to claim 1, characterized in that, The calculation model for the actual cooling rate is: Ks = ΔT / Δt; Wherein, Ks is the actual cooling rate, ΔT is the return gas temperature drop value within a preset time, and Δt is the preset time.

12. The refrigerant condition diagnosis method according to claim 1, characterized in that, The calculation model for the cooling rate deviation is: δK=Ks / Ki; Wherein, δK is the cooling rate deviation value, Ks is the actual cooling rate, and Ki is the theoretical cooling rate.

13. The refrigerant condition diagnosis method according to claim 1, characterized in that, The calculation model for the operating current deviation value is: δI=Is / Ii; Wherein, δI is the operating current deviation value, Is is the average operating current, and Ii is the standard operating current.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the refrigerant status diagnosis method as described in any one of claims 1 to 13.

15. A refrigerator, characterized in that, The refrigerator has a computer-readable storage medium as described in claim 14.

Images