Temperature control method after fault of temperature sensor of frequency conversion refrigerator

Abstract

The invention provides a temperature control method after a fault of a temperature sensor of a frequency conversion refrigerator, and relates to the field of household appliances. Calculating the average refrigeration power of each chamber according to the refrigeration data; whether the sensor breaks down or not is detected, and when the sensor breaks down, the refrigerator is in a fault operation mode; presetting a compressor target starting rate range, a compressor default rotating speed and a starting and stopping period, and calculating starting time required by each chamber; checking the starting rate according to the starting time required by each chamber to obtain the final rotating speed of the compressor; according to the method, the refrigerating time and the rotating speed of the compressor are reversely calculated according to the refrigerating capacity needed by each chamber, accurate refrigerating time distribution is carried out according to historical data, and therefore the method is more suitable for the actual use environment of a user, and the user experience is improved. And the influence of temperature fluctuation on food preservation is reduced.

Description

Technical Field

[0001] The present application relates to the field of household appliances, and in particular to a temperature control method after a temperature sensor of a variable frequency refrigerator fails. Background Art

[0002] The temperature control of existing refrigerators is achieved by detecting the temperature sensors in the refrigeration and freezing compartments, controlling the start and stop and speed of the compressor according to the temperature changes of the sensors, so as to control the compartment temperature in a relatively stable range.

[0003] In actual applications, temperature sensors work in cold, hot, dry, and wet environments for a long time, and are prone to sensor failure due to water vapor erosion, thermal expansion, and contraction. After sensor failure, the general practice is to alternately refrigerate each compartment at a fixed time to retain basic refrigeration capacity rather than completely stop working to avoid damage to food in the refrigerator.

[0004] Some technical documents also disclose a method of using the refrigeration time and refrigeration stop time of each compartment during normal operation recorded on the refrigerator end or uploaded to the cloud to calculate the average refrigeration time and the average downtime. When a sensor failure is detected, the calculated average refrigeration time and the average downtime are used to control the refrigeration.

[0005] Because the working temperature of the refrigerator, the condition of the stored food and the user's usage habits vary greatly, fixed-time refrigeration often causes the temperature in the room to be too cold or too hot.

[0006] In actual work, the operation of the refrigerator is closely related to the user's usage environment, such as the ambient temperature in the home, the heat dissipation and ventilation conditions of the placement, the condition of the stored food, etc. When the ambient temperature is higher, the heat dissipation conditions are worse, and the more food is stored, the compressor needs to run for a longer time and at a higher speed. Conversely, it needs to run for a shorter time and at a lower speed.

[0007] However, as mentioned above, the solution of alternating cooling of each compartment at a fixed time is very likely to cause the temperature to be too cold or too hot under the widely varying usage environments of users, which in turn leads to problems such as thawing of meat and freezing of vegetables. A more adaptable solution is needed.

[0008] As for the method of using the average refrigeration time and the average downtime during normal operation, it can improve the accuracy of temperature control after sensor failure to a certain extent. However, for refrigerators using variable frequency compressors, the refrigeration capacity of the compressor at different speeds varies greatly. Simply recording the average refrigeration time of different compartments during normal operation cannot effectively represent the refrigeration capacity required in the current use environment. Therefore, simply using time to control accuracy is still insufficient, and factors such as the compressor speed need to be considered comprehensively. Summary of the invention

[0009] The embodiment of the present application provides a temperature control method after a variable frequency refrigerator temperature sensor fails. The method calculates the refrigeration capacity required for each compartment by recording the refrigeration time and compressor speed changes of each compartment when the refrigerator is working normally. When the sensor fails, the refrigeration time and compressor speed are calculated based on the refrigeration capacity required for each compartment, rather than simply relying on a fixed time or historical average refrigeration time for control. Accurate refrigeration time allocation is performed based on these historical data, thereby better fitting the user's actual use environment and reducing the impact of temperature fluctuations on food preservation. The present application solves the problem of inaccurate temperature control caused by temperature sensor failure in existing refrigerator temperature control systems.

[0010] The embodiment of the present application provides a method for controlling temperature after a temperature sensor of a variable frequency refrigerator fails, comprising:

[0011] Collect refrigeration data of refrigerators in normal operation mode;

[0012] Calculate the average cooling power of each compartment through the cooling data;

[0013] Detect whether the sensor fails. If the sensor fails, the refrigerator will enter the failure operation mode, including:

[0014] Preset the compressor target startup rate range, compressor default speed and startup and shutdown cycle, and calculate the startup time required for each compartment;

[0015] According to the startup time required by each room, the startup rate is calculated to obtain the final compressor speed;

[0016] The refrigeration is controlled according to the startup time and the final compressor speed required for each compartment.

[0017] In a feasible implementation, the detection sensor is checked to see if it fails. When the sensor does not fail, the refrigerator enters a normal operation mode.

[0018] In a feasible implementation, the temperature control method further includes:

[0019] While the refrigerator is in fault operation mode, it continuously detects whether the sensor has returned to normal and records the time of return to normal;

[0020] When the sensor returns to normal for 12 hours, the refrigerator switches to the normal operating mode;

[0021] If the sensor does not return to normal, or the time to return to normal is less than 12 hours, the refrigerator will continue to operate in fault mode.

[0022] In a feasible implementation, the calculating the average cooling power of each compartment by using the cooling data specifically includes:

[0023] Calculate the cooling capacity of each room during single cooling;

[0024] According to the cooling capacity of each compartment during a single cooling, calculate the total cooling capacity of each compartment within a rolling 72-hour period;

[0025] Calculating the total operating time according to the refrigeration data;

[0026] The average cooling power of each compartment is calculated based on the total operating time and the total cooling capacity of each compartment within a rolling 72-hour period.

[0027] In a feasible implementation, for the variable frequency compressor, the speed s of the compressor and its refrigeration power p have a functional relationship p=f(s). When the refrigerator is in normal operation mode, the compressor is calculated with a rolling speed s. on1 Running time t on1 , Shutdown off1 Time, speed s on2 Run on2 Time, downtime off2 Time...Speed ​​s onn Run onn Time, downtime offn Time, within each time period;

[0028] The calculation of the cooling capacity of each compartment during a single cooling operation specifically includes:

[0029] If the refrigeration is frozen, the refrigeration capacity of this refrigeration is q ldn =p ldn ×t onn =f(s onn )×t onn ;

[0030] If variable temperature cooling is used, the cooling capacity of this variable temperature is q bwn =p bwn ×t onn =f(s onn )×t onn ;

[0031] If the refrigeration is refrigerated, the refrigeration capacity of the refrigeration is q lcn =p lcn ×t onn =f(s onn )×t onn .

[0032] In a feasible implementation, the calculation of the total refrigeration capacity of each compartment within a rolling 72-hour period specifically includes:

[0033] Total refrigeration capacity

[0034] Total cooling capacity of variable temperature

[0035] Total refrigeration capacity

[0036] In a feasible implementation, the calculating the total running time specifically includes:

[0037]

[0038] In a feasible implementation, the calculating the average cooling power of each compartment specifically includes:

[0039] Total refrigeration capacity P ld =Q ld ÷T total ;

[0040] Total cooling capacity of variable temperature P bw =Q bw ÷T total ;

[0041] Total refrigeration capacity P lc =Q lc ÷T total .

[0042] In a feasible implementation, the preset compressor target startup rate range, the compressor default speed and the startup and shutdown cycle, and the calculation of the startup time required for each compartment specifically include:

[0043] Preset the compressor target start-up rate range η0, the compressor default speed s0, and the start-stop cycle T;

[0044] Calculate the startup time required for each room:

[0045] Refrigeration start time

[0046] Variable temperature start time

[0047] Refrigeration start time

[0048] In a feasible implementation, according to the startup time required by each compartment, the startup rate is verified and calculated to obtain the final compressor speed, specifically including:

[0049]

[0050] If η>η0, the default speed is increased by one gear, and the system returns to S6 and S7 to calculate the startup time distribution and recalculate the startup rate until the startup rate is satisfied. At this time, the speed is s. If the system still does not meet the requirement after increasing to the highest gear, the system will execute at the highest gear.

[0051] If η<η0, the default speed will be reduced by one gear, and the system will return to S5 and S6 to calculate the startup time distribution and recalculate the startup rate until the startup rate is met. At this time, the speed is s. If it is still not met after dropping to the lowest gear, the system will execute at the lowest gear.

[0052] The embodiment of the present application provides a method for controlling the temperature of a variable frequency refrigerator after a temperature sensor fails. The method calculates the refrigeration capacity required for each compartment by recording the refrigeration time and compressor speed changes of each compartment when the refrigerator is working normally. When the sensor fails, the refrigeration time and compressor speed are calculated based on the refrigeration capacity required for each compartment, rather than simply relying on a fixed time or historical average refrigeration time for control. Accurate refrigeration time allocation is performed based on these historical data, thereby better fitting the actual use environment of the user and reducing the impact of temperature fluctuations on food preservation. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a flow chart of a temperature control method after a variable frequency refrigerator temperature sensor fails provided by the present application. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0055] In the prior art, refrigerators usually rely on temperature sensors to monitor the temperature of the refrigerator and freezer in real time, so as to maintain the stability of the temperature in the compartment by adjusting the start and stop and speed of the compressor. However, due to the complex working environment of the refrigerator, the sensor is exposed to the alternating environment of cold, hot, dry and wet for a long time, and is prone to failure due to water vapor erosion, thermal expansion and contraction, etc. When the sensor fails, the traditional treatment method is to maintain the basic operation of the refrigerator by refrigerating for a fixed time, or to record and calculate the average refrigeration time of each compartment before the sensor fails. However, this method cannot adapt to the use environment of different users, which often leads to the temperature of the refrigerator or freezer being too high or too low, thereby affecting the preservation effect of food, and even causing problems such as thawing of meat or freezing of vegetables.

[0056] Based on this, the present application proposes a new temperature control solution, which calculates the refrigeration capacity required for each compartment through the refrigeration time and compressor speed changes recorded in each compartment when the refrigerator is working normally. When the sensor fails, the refrigeration time and compressor speed are calculated based on the refrigeration capacity required for each compartment, instead of simply relying on fixed time or historical average refrigeration time for control. Accurate refrigeration time allocation is performed based on these historical data, so as to better fit the user's actual use environment and reduce the impact of temperature fluctuations on food preservation. At the same time, the system will continue to monitor the sensor status. Once the sensor returns to normal, the system will automatically exit the fault mode and resume normal operation. This solution not only improves the temperature control accuracy of the refrigerator in the event of sensor failure, but also buys users enough time for repairs and avoids the risk of food damage.

[0057] The temperature control method after a temperature sensor failure of a variable frequency refrigerator provided by the present application is described in detail below in conjunction with the accompanying drawings.

[0058] The technical solution of the present invention is described by taking a refrigerator with three temperature zones of refrigeration, freezing and variable temperature as an example, and the same can be applied to refrigerators with more temperature zones. As described in the background technology, damage to the sensor usually occurs due to water vapor erosion, thermal expansion and contraction after long-term use, that is, normal temperature control can be performed before the sensor is damaged.

[0059] Furthermore, in a relatively short period of time, such as within a week, the user's usage environment generally does not change significantly. Based on this background, the present invention proposes to use the refrigerator to continuously and rollingly record the start and stop timing and the compressor speed calculated by the intact temperature sensor when the refrigerator is operating normally, that is, the refrigeration capacity distribution law of each compartment. When the temperature sensor is damaged, the refrigeration time and compressor speed required for each compartment are reversely calculated according to the refrigeration capacity distribution law, and then the refrigeration control is performed according to the refrigeration time and compressor speed, thereby achieving more accurate control accuracy than simple time control, so that the user has enough time to report the refrigerator for repair, so as to avoid damage to food due to overcooling or overheating.

[0060] First, collect the cooling capacity distribution rules of the refrigerator under normal working conditions.

[0061] When the refrigerator is powered on for the first time, there is a slow cooling process. The stored food also needs time to reach equilibrium with the air temperature in the refrigerator, which usually takes more than 24 hours. Therefore, the data within 24 hours after power-on is eliminated, and the following steps are calculated from 24 hours later. At the same time, in order to avoid the influence of defrosting and door opening on the data, the data of one refrigeration cycle before and after defrosting and the refrigeration cycle with door opening action are eliminated.

[0062] like Figure 1As shown in the figure, for variable frequency compressors, the speed s of the compressor and its refrigeration power p have a functional relationship p = f(s), and the rolling data collection time for the refrigerator working in the normal state of the sensor is preset to be 72 hours. When the refrigerator is working normally, the rolling calculation of the compressor at the speed s on1 Running time t on1 , Shutdown off1 Time, speed s on2 Run on2 Time, downtime off2 Time...Speed ​​s onn Run onn Time, downtime offn Time, within each time period:

[0063] S1: Calculate the cooling capacity of each room during a single cooling operation;

[0064] If the refrigeration is frozen, the refrigeration capacity of this refrigeration is q ldn =p ldn ×t onn =f(s onn )×t onn ;

[0065] If variable temperature cooling is used, the cooling capacity of this variable temperature is q bwn =p bwn ×t onn =f(s onn )×t onn ;

[0066] If the refrigeration is refrigerated, the refrigeration capacity of the refrigeration is q lcn =p lcn ×t onn =f(s onn )×t onn .

[0067] S2: Calculate the total cooling capacity of each room within 72 rolling hours;

[0068] Total refrigeration capacity

[0069] Total cooling capacity of variable temperature

[0070] Total refrigeration capacity

[0071] S3: Calculate the total running time;

[0072] Since the start and stop timing of the compressor is determined by the temperature of the sensor, it does not necessarily shut down exactly at the scheduled 72 hours, so there is a slight deviation between the total running time and 72 hours.

[0073] S4: Calculate the average cooling power of each compartment;

[0074] Total refrigeration capacity P ld =Q ld ÷T total ;

[0075] Total cooling capacity of variable temperature P bw =Q bw ÷T total ;

[0076] Total refrigeration capacity P lc =Q lc ÷T total ;

[0077] When a sensor failure is detected, the compressor speed and time are allocated according to the calculation results.

[0078] S5: When a sensor failure is detected, the compressor target startup rate range η0, the compressor default speed s0, and the start-stop cycle T are preset.

[0079] S6: Calculate the startup time required for each room:

[0080] Refrigeration start time

[0081] Variable temperature start time

[0082] Refrigeration start time

[0083] S7: Verify the startup rate:

[0084]

[0085] If η>η0, the default speed is increased by one gear, and the system returns to S6 and S7 to calculate the startup time distribution and recalculate the startup rate until the startup rate is satisfied. At this time, the speed is s. If the system still does not meet the requirement after increasing to the highest gear, the system will execute at the highest gear.

[0086] If η<η0, the default speed will be reduced by one gear, and the system will return to S5 and S6 to calculate the startup time distribution and recalculate the startup rate until the startup rate is met. At this time, the speed is s. If it is still not met after dropping to the lowest gear, the system will execute at the lowest gear.

[0087] S8: Control refrigeration based on the calculation results:

[0088] According to the freezing time T ld , variable temperature cooling time T bw , Refrigeration time T lc , downtime T-(T ld +Tbw +T lc ) and the compressor speed s cycles to control refrigeration.

[0089] When operating in the sensor fault mode, the status of each sensor is continuously monitored. In practice, poor contact failures often occur, which manifest as the sensor sometimes working normally and sometimes failing within a short period of time. If the sensor is monitored to return to normal for 12 hours in the fault operation mode, the fault operation mode is exited and the normal operation mode is restored. If the sensor does not return to normal, or the recovery time does not reach 12 hours, the status of each sensor will continue to be monitored.

[0090] The above algorithm requires a small amount of computation and storage, and is easy to implement on a microcontroller with small computing power and storage at the refrigerator end, without adding hardware and cost, and is easy to implement. Through the above method, a fault operation rule after a temperature sensor fault is realized that is more suitable for the actual user environment.

[0091] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments based on the several embodiments provided in the present application, and these embodiments do not exceed the protection scope of the present application.

[0092] The above specific implementation methods further explain in detail the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above are only specific implementation methods of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A temperature control method for a variable frequency refrigerator after a temperature sensor fails, characterized in that: include; Collect refrigeration data of refrigerators in normal operation mode; Calculate the average cooling power of each compartment through the cooling data; Detect whether the sensor fails. If the sensor fails, the refrigerator will enter the failure operation mode, including: Preset the compressor target startup rate range, compressor default speed and startup and shutdown cycle, and calculate the startup time required for each compartment; According to the startup time required by each room, the startup rate is calculated to obtain the final compressor speed; The refrigeration is controlled according to the startup time and the final compressor speed required for each compartment.

2. The temperature control method after a frequency conversion refrigerator temperature sensor failure according to claim 1 is characterized in that: The detection sensor is configured to detect whether a fault occurs. When the sensor does not fail, the refrigerator enters a normal operation mode.

3. The temperature control method after a frequency conversion refrigerator temperature sensor failure according to claim 1 or 2, characterized in that: The temperature control method also includes: While the refrigerator is in fault operation mode, it continuously detects whether the sensor has returned to normal and records the time of return to normal; When the sensor returns to normal for 12 hours, the refrigerator switches to the normal operating mode; If the sensor does not return to normal, or the time to return to normal is less than 12 hours, the refrigerator will continue to operate in fault mode.

4. The temperature control method after a frequency conversion refrigerator temperature sensor failure according to claim 1, characterized in that: The calculating the average cooling power of each compartment through the cooling data specifically includes: Calculate the cooling capacity of each room during single cooling; According to the cooling capacity of each compartment during a single cooling, calculate the total cooling capacity of each compartment within a rolling 72-hour period; Calculating the total operating time according to the refrigeration data; The average cooling power of each compartment is calculated based on the total operating time and the total cooling capacity of each compartment within a rolling 72-hour period.

5. The temperature control method after a frequency conversion refrigerator temperature sensor failure according to claim 4 is characterized in that: For variable frequency compressors, the speed s of the compressor and its refrigeration power p have a functional relationship p = f(s). When the refrigerator is in normal operation mode, the rolling calculation of the compressor speed s on1 Running time t on1 , Shutdown off1 Time, speed s on2 Run on2 Time, downtime off2 Time...Speed ​​s onn Run onn Time, downtime offn Time, within each time period; The calculation of the cooling capacity of each compartment during a single cooling operation specifically includes: If the refrigeration is frozen, the refrigeration capacity of this refrigeration is q ldn =p ldn ×t onn =f(s onn )×t onn ; If variable temperature cooling is used, the cooling capacity of this variable temperature is q bwn =p bwn ×t onn =f(s onn )×t onn ; If the refrigeration is refrigerated, the refrigeration capacity of the refrigeration is q lcn =p lcn ×t onn =f(s onn )×t onn .

6. The temperature control method after a frequency conversion refrigerator temperature sensor failure according to claim 5, characterized in that: The calculation of the total refrigeration capacity of each compartment within a rolling 72-hour period specifically includes: Total refrigeration capacity Total cooling capacity of variable temperature Total refrigeration capacity 7. The temperature control method after a frequency conversion refrigerator temperature sensor failure according to claim 6, characterized in that: The calculation of the total running time specifically includes:

8. The temperature control method for a variable frequency refrigerator after a temperature sensor failure according to claim 7, characterized in that: The calculating of the average cooling power of each compartment specifically includes: Total refrigeration capacity P ld =Q ld ÷T total ; Total cooling capacity of variable temperature P bw =Q bw ÷T total ; Total refrigeration capacity P lc =Q lc ÷T total .

9. The temperature control method after a temperature sensor failure of a variable frequency refrigerator according to claim 8, characterized in that: The preset compressor target startup rate range, compressor default speed and startup and shutdown cycle, and calculation of the startup time required for each compartment specifically include: Preset the compressor target start-up rate range η0, the compressor default speed s0, and the start-stop cycle T; Calculate the startup time required for each room: Refrigeration start time Variable temperature start time Refrigeration start time 10. The temperature control method after a temperature sensor failure of a variable frequency refrigerator according to claim 9, characterized in that: The method of calculating the startup rate according to the startup time required by each compartment to obtain the final compressor speed specifically includes: If η>η0, the default speed is increased by one gear, and the system returns to S6 and S7 to calculate the startup time distribution and recalculate the startup rate until the startup rate is satisfied. At this time, the speed is s. If the system still does not meet the requirement after increasing to the highest gear, the system will execute at the highest gear. If η<η0, the default speed will be reduced by one gear, and the system will return to S5 and S6 to calculate the startup time distribution and recalculate the startup rate until the startup rate is met. At this time, the speed is s. If it is still not met after dropping to the lowest gear, the system will execute at the lowest gear.

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