A temperature control method after a temperature sensor of a variable frequency refrigerator fails

Abstract

The application provides a temperature control method after a temperature sensor of a variable frequency refrigerator fails, and relates to the field of household appliances, which comprises collecting refrigeration data of the refrigerator in a normal operation mode; calculating average refrigeration power of each compartment through the refrigeration data; detecting whether the sensor fails, and when the sensor fails, the refrigerator operates in a failure operation mode, which specifically comprises: presetting a target starting rate range of a compressor, a default rotating speed of the compressor and a start-stop cycle, and calculating starting time required by each compartment; calculating a starting rate according to the starting time required by each compartment to obtain a final rotating speed of the compressor; and controlling refrigeration according to the starting time required by each compartment and the final rotating speed of the compressor. According to the application, the refrigeration time and the rotating speed of the compressor are inversely calculated according to the required refrigeration amount of each compartment, and accurate refrigeration time distribution is performed according to historical data, so that the actual use environment of the user is more fitted, 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, in particular to a temperature control method after a temperature sensor of a variable frequency refrigerator fails. BACKGROUND

[0002] The temperature control of the existing refrigerator is to detect the temperature sensor in the refrigeration, freezing and other compartments, control the start and stop and speed of the compressor according to the temperature change of the sensor, so as to control the compartment temperature in a relatively stable range.

[0003] In actual application, the temperature sensor works in a cold, hot, dry and wet alternating environment for a long time, which is easy to cause the sensor to fail due to water vapor erosion, thermal expansion and contraction and other problems. After the sensor fails, the general practice is to alternate refrigeration for a fixed time in each compartment, and to retain the basic refrigeration capacity instead of completely stopping work, so as to avoid the damage of food in the refrigerator.

[0004] In some technical documents, a method is also disclosed, which uses the refrigeration time and stop refrigeration time of each compartment recorded at the end of the refrigerator or uploaded to the cloud during normal operation to calculate the average refrigeration time and average downtime, and uses the calculated average refrigeration time and average downtime to control the refrigeration when the sensor fails is detected.

[0005] Because the working temperature of the refrigerator, the food condition and the user's use habit are different, fixed time refrigeration often leads to overcooling or overheating in the compartment.

[0006] In actual work, the operation of the refrigerator and the use environment of the user, such as the environmental temperature at home, the heat dissipation and ventilation conditions of the placement position, the storage food condition, etc. are closely related. When the environmental temperature is higher, the heat dissipation condition is worse, and the stored food is more, the compressor needs to run for a longer time and at a higher speed, and vice versa.

[0007] But as mentioned above, the scheme of alternating refrigeration for a fixed time in each compartment is very easy to cause overcooling or overheating in the user's different use environment, and further cause problems such as thawing of meat and freezing of vegetables, which needs a more adaptive solution.

[0008] As for the method of using the average refrigeration time and average downtime during normal time, it can improve the accuracy of temperature control after the sensor fails to a certain extent. However, for the refrigerator using a variable frequency compressor, the refrigeration capacity of the compressor at different speeds is very different, and simply recording the average refrigeration time of different compartments during normal operation cannot effectively represent the required refrigeration capacity in the current use environment, so simply using time to control the accuracy is still insufficient, and factors such as compressor speed also need to be considered. SUMMARY

[0009] The embodiment of the present application provides a temperature control method after a temperature sensor of a variable frequency refrigerator fails, the refrigeration time of each compartment, the change of compressor speed recorded when the refrigerator normally works, the refrigeration amount required by each compartment is calculated through the refrigeration time and the compressor speed. When the sensor fails, the refrigeration time and the compressor speed are calculated reversely according to the refrigeration amount required by each compartment, instead of simply relying on fixed time or historical average refrigeration time for control, and the accurate refrigeration time distribution is performed according to the historical data, so that the actual use environment of the user is more fitted, and the influence of temperature fluctuation on food preservation is reduced. The present application solves the problem of inaccurate temperature control caused by the failure of the temperature sensor in the existing refrigerator temperature control system.

[0010] The embodiment of the present application provides a temperature control method after a temperature sensor of a variable frequency refrigerator fails, the refrigeration time of each compartment, the change of compressor speed recorded when the refrigerator normally works, the refrigeration amount required by each compartment is calculated through the refrigeration time and the compressor speed. When the sensor fails, the refrigeration time and the compressor speed are calculated reversely according to the refrigeration amount required by each compartment, instead of simply relying on fixed time or historical average refrigeration time for control, and the accurate refrigeration time distribution is performed according to the historical data, so that the actual use environment of the user is more fitted, and the influence of temperature fluctuation on food preservation is reduced. The present application solves the problem of inaccurate temperature control caused by the failure of the temperature sensor in the existing refrigerator temperature control system.

[0011] Collecting refrigeration data of the refrigerator in a normal operation mode;

[0012] Calculating the average refrigeration power of each compartment through the refrigeration data;

[0013] Detecting whether the sensor fails, when the sensor fails, the refrigerator performs a failure operation mode, and specifically comprising:

[0014] Pre-setting a compressor target starting rate range, a compressor default speed and a start-stop cycle, and calculating the starting time required by each compartment;

[0015] According to the starting time required by each compartment, the starting rate is calculated, and the final compressor speed is obtained;

[0016] According to the starting time required by each compartment and the final compressor speed, the refrigeration is controlled.

[0017] In a feasible implementation manner, when the sensor does not fail, the refrigerator performs a normal operation mode.

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

[0019] When the refrigerator performs the failure operation mode, whether the sensor recovers normally is continuously detected, and the time when the sensor recovers normally is recorded;

[0020] When the sensor recovers normally for 12 hours, the refrigerator switches to the normal operation mode;

[0021] When the sensor does not recover normally or the time when the sensor recovers normally does not reach 12 hours, the refrigerator continues to perform the failure operation mode.

[0022] In an implementation, the calculating the average refrigeration power of each compartment based on the refrigeration data comprises:

[0023] calculating the refrigeration amount of each compartment in a single refrigeration;

[0024] calculating the total refrigeration amount of each compartment in a rolling 72 hours according to the refrigeration amount of each compartment in a single refrigeration;

[0025] calculating the total running time according to the refrigeration data;

[0026] calculating the average refrigeration power of each compartment according to the total running time and the total refrigeration amount of each compartment in a rolling 72 hours.

[0027] In an implementation, for a variable frequency compressor, the rotating speed s of the compressor has a function relationship p=f(s) with the refrigeration power p of the compressor, and when the refrigerator is in a normal operation mode, the compressor is calculated in a rolling manner with the rotating speed s on1 running time t on1 , stop time t off1 , rotating speed s on2 running time t on2 , stop time t off2 , rotating speed s onn running time t onn , stop time t offn , rotating speed s in each time period.

[0028] The calculating the refrigeration amount of each compartment in a single refrigeration comprises:

[0029] If the refrigeration is freezing, the refrigeration amount q ldn of this freezing is calculated as p ldn ×t onn =f(s onn )×t onn .

[0030] If the refrigeration is variable temperature refrigeration, the refrigeration amount q bwn of this variable temperature refrigeration is calculated as p bwn ×t onn =f(s onn )×t onn .

[0031] If the refrigeration is refrigeration, the refrigeration amount q lcn of this refrigeration is calculated as p lcn ×t onn =f(s onn )×t onn .

[0032] In an implementation, the calculating the total refrigeration amount of each compartment in a rolling 72 hours comprises:

[0033] Total refrigeration capacity of freezing

[0034] Total refrigeration capacity of variable temperature

[0035] Total refrigeration capacity of refrigeration

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

[0037]

[0038] In an implementation, the calculating average refrigeration power of each compartment specifically includes:

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

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

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

[0042] In an implementation, the preset compressor target starting rate range, compressor default speed and start-stop cycle are calculated, and the required starting time of each compartment is calculated, specifically including:

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

[0044] Calculate the required starting time of each compartment:

[0045] Freezing starting time

[0046] Variable temperature starting time

[0047] Refrigeration starting time

[0048] In an implementation, according to the required starting time of each compartment, the starting rate is calculated, and the final compressor speed is obtained, specifically including:

[0049]

[0050] If η > η0, the default speed will be increased by one gear, and return to S6, S7 to calculate the start-up time distribution and recheck the start-up probability, until the start-up probability meets, at this time the speed is s, if it is still not satisfied after rising to the highest gear, it will be executed according to the highest gear;

[0051] If η < η0, the default speed will be decreased by one gear, and return to S5, S6 to calculate the start-up time distribution and recheck the start-up probability, until the start-up probability meets, at this time the speed is s, if it is still not satisfied after falling to the lowest gear, it will be executed according to the lowest gear.

[0052] The temperature control method provided by the embodiment of the present application after the temperature sensor of the variable frequency refrigerator fails, through the refrigeration time of each compartment and the change of the compressor speed recorded when the refrigerator is normally working, the refrigeration amount required by each compartment is calculated through the refrigeration time and the compressor speed. When the sensor fails, the refrigeration time and the compressor speed are recalculated according to the refrigeration amount required by each compartment, instead of simply relying on the fixed time or the historical average refrigeration time for control, and the accurate refrigeration time distribution is performed according to the historical data, so that the actual use environment of the user is more fitted, and the influence of temperature fluctuation on food preservation is reduced. BRIEF DESCRIPTION OF DRAWINGS

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

[0054] In order for 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 combination 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 the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0055] In the prior art, the refrigerator usually relies on the temperature sensor to monitor the temperature of the refrigeration compartment and the freezing compartment in real time, so as to maintain the stability of the temperature in the compartment by adjusting the start-stop and speed of the compressor. However, due to the complex working environment of the refrigerator, the sensor is exposed to the environment of alternating cold, heat, dry and wet for a long time, and is prone to failure due to water vapor erosion, thermal expansion and contraction and other reasons. When the sensor fails, the traditional processing method is to maintain the basic operation of the refrigerator by fixed time refrigeration, or to use the average refrigeration time of each compartment before the sensor fails is recorded and calculated, but this method cannot adapt to the use environment of different users, and often leads to too high or too low temperature in the refrigeration compartment or the freezing compartment, thereby affecting the preservation effect of food, and even causing meat thawing or vegetable freezing and other problems.

[0056] Based on this, the application proposes a new temperature control scheme. The cooling time of each compartment and the change of compressor speed are recorded when the refrigerator is working normally. The cooling capacity required by each compartment is calculated based on the cooling time and the compressor speed. When the sensor fails, the cooling time and the compressor speed are recalculated based on the cooling capacity required by each compartment, instead of simply relying on fixed time or historical average cooling time for control. The historical data is used to accurately allocate the cooling time, so as to better fit the actual use environment of the user and reduce the impact of temperature fluctuations on food preservation. At the same time, the system continuously monitors the sensor state. Once the sensor returns to normal, the system will automatically exit the fault mode and resume normal operation. This scheme not only improves the temperature control accuracy of the refrigerator in the case of sensor failure, but also gives the user enough time to repair and avoid the risk of food damage.

[0057] The temperature control method of the variable frequency refrigerator after the temperature sensor fails provided by the application will be described in detail below with reference to the accompanying drawings.

[0058] The technical scheme of the application is illustrated by taking a refrigerator with three temperature zones of refrigeration, freezing and variable temperature as an example. The case of a refrigerator with more temperature zones can be analogized. As described in the background, the damage of the sensor usually occurs after long-term use due to water vapor erosion, thermal expansion and contraction, etc. That is, normal temperature control can be performed before the sensor is damaged.

[0059] Further, in a short period of time such as a week, the user's use environment generally does not change much. Based on this background, the application proposes to use the cooling capacity distribution rule calculated by the refrigerator based on the intact temperature sensor during normal operation to calculate the cooling time and compressor speed required by each compartment when the temperature sensor fails. Then, the cooling control is performed based on the cooling time and compressor speed, so as to achieve more accurate control accuracy than simple time control, give the user enough time to repair the refrigerator, and avoid the damage of food caused by overcooling or overheating.

[0060] First, the cooling capacity distribution rule of the refrigerator under normal working conditions is collected.

[0061] The refrigerator has a slow cooling process when it is powered on for the first time. The food stored also needs time and air temperature in the refrigerator to reach equilibrium, which generally takes more than 24 hours. Therefore, the data within 24 hours after power-on is excluded. The following steps start to calculate from 24 hours later. In order to avoid the influence of defrosting and opening the door on the data, the data of one cooling period before and after defrosting and the data of the cooling period with opening the door are excluded.

[0062] For example, the cooling capacity distribution rule of the refrigerator is shown in the following table. Figure 1As shown, for the variable frequency compressor, the compressor speed *s* has a functional relationship with its cooling power *p*, p = f(s), and the preset data collection time for the refrigerator operating under normal sensor conditions is 72 hours. When the refrigerator is operating normally, the compressor speed *s* is calculated to be... on1 Running time t on1 Shutdown off1 Time, rotational speed (s) on2 Run t on2 Time, downtime t off2 Time... Rotation speed (s) onn Run t onn Time, downtime t offn Time, within each time period:

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

[0064] If freezing is used, the cooling capacity q for this freezing operation is... ldn =p ldn ×t onn =f(s) onn )×t onn ;

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

[0066] If refrigeration is used, the refrigeration capacity q for this refrigeration operation is... lcn =p lcn ×t onn =f(s) onn )×t onn .

[0067] S2: Calculate the total cooling capacity of each room during the 72-hour rolling cycle;

[0068] Total refrigeration capacity

[0069] Total cooling capacity for variable temperature

[0070] Total refrigeration capacity

[0071] S3: Calculate the total running time;

[0072] Because the compressor's start-up and shutdown timing is determined by the sensor's temperature, it may not necessarily stop exactly at the predetermined 72-hour mark, so there is a slight deviation between the total running time and the 72-hour timeframe.

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

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

[0075] Total refrigeration capacity 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, preset the compressor target startup rate range η0, the compressor default speed s0, and the start-stop cycle T.

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

[0080] Freezing startup time

[0081] Thermostat startup time

[0082] Refrigeration startup time

[0083] S7: Check the startup rate:

[0084]

[0085] If η > η0, increase the default speed by one step, and return to S6 and S7 to calculate the startup time allocation and check the startup rate again until the startup rate meets η = η0, at which point the speed is s. If it is still not satisfied after increasing to the highest step, execute it according to the highest step;

[0086] If η < η0, decrease the default speed by one step, and return to S5 and S6 to calculate the startup time allocation and check the startup rate again until the startup rate meets η = η0, at which point the speed is s. If it is still not satisfied after decreasing to the lowest step, execute it according to the lowest step.

[0087] S8: Control refrigeration according to the calculation results:

[0088] According to the freezing refrigeration time T ld , the thermostat refrigeration time T bw , the refrigeration refrigeration time T lc , and the shutdown time T-(T ld +Tbw +T lc ), compressor speed s cycle control refrigeration.

[0089] When running in the sensor fault mode, the state of each sensor is continuously monitored. In practice, the form of poor contact fault often occurs, which is manifested as the sensor being normal at times and faulty at times within a short period of time. If the sensor is continuously monitored for 12 hours and returns to normal in the fault running mode, the fault running mode is exited and the normal running mode is resumed. If the sensor does not return to normal or the time for which the sensor returns to normal does not reach 12 hours, the state of each sensor is continuously monitored.

[0090] The calculation amount and storage amount required by the above algorithm are relatively small, and the algorithm is easy to implement on a microcontroller with small calculation and storage capacity at the refrigerator end without increasing hardware and cost. Through the above method, a fault running rule after a temperature sensor fault that is more suitable for the actual use environment of a user is realized.

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

[0092] The above specific embodiments further specifically describe the purposes, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above is only a specific embodiment of the present application and is not used to limit the protection scope of the embodiments of the present application. Any modification, equivalent replacement, improvement, 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 malfunction, characterized in that: include; Collect refrigeration data of the refrigerator in normal operating mode; The average cooling power of each room is calculated using the cooling data. The refrigerator detects whether the sensor is malfunctioning. If the sensor is malfunctioning, the refrigerator will enter a fault operation mode, which includes: The system presets the target compressor uptime range, the compressor default speed, and the start-stop cycle, and calculates the required uptime for each compartment. Based on the required start-up time for each compartment, the start-up rate is calculated to obtain the final compressor speed; The system operates according to the required start-up time and final compressor speed for each compartment to control refrigeration.

2. The temperature control method for a variable frequency refrigerator after a temperature sensor malfunction, as described in claim 1, is characterized in that: The detection sensor is checked for malfunctions. If the sensor is not malfunctioning, the refrigerator will operate in normal mode.

3. The temperature control method for a variable frequency refrigerator after a temperature sensor malfunction, as described in claim 1 or 2, is characterized in that: Temperature control methods also include; While the refrigerator is in fault operation mode, it continuously monitors whether the sensors have returned to normal and records the time it takes to return to normal. If the sensor returns to normal after 12 hours, the refrigerator will switch to the normal operating mode. If the sensor does not return to normal, or if the time required for it to return to normal is less than 12 hours, the refrigerator will continue to operate in fault mode.

4. The temperature control method for a variable frequency refrigerator after a temperature sensor failure according to claim 1, characterized in that: The step of calculating the average cooling power of each room using the cooling data specifically includes: Calculate the cooling capacity of each room during a single cooling cycle; Calculate the total cooling capacity of each room over a 72-hour rolling period based on the cooling capacity of each room during a single cooling cycle. Calculate the total running time based on the cooling data; The average cooling power of each room is calculated based on the total operating time and the total cooling capacity of each room over a 72-hour rolling period.

5. The temperature control method for a variable frequency refrigerator after a temperature sensor failure, as described in claim 4, is characterized in that: For a variable frequency compressor, the compressor speed *s* has a functional relationship with its cooling power *p*, where *p* = *f(s)*. When the refrigerator is in normal operating mode, the compressor speed *s* is calculated continuously. on1 Running time t on1 Shutdown off1 Time, rotational speed (s) on2 Run t on2 Time, downtime t off2 Time... Rotation speed (s) onn Run t onn Time, downtime t offn Time, within each time period; The calculation of the cooling capacity of each room during a single cooling cycle specifically includes: If freezing is used, the cooling capacity q for this freezing operation is... ldn =p ldn ×t onn =f(s) onn )×t onn ; If the refrigeration is variable temperature, the refrigeration capacity q during this variable temperature process... bwn =p bwn ×t onn =f(s) onn )×t onn ; If refrigeration is used, the refrigeration capacity q for this refrigeration operation is... lcn =p lcn ×t onn =f(s) onn )×t onn .

6. The temperature control method for a variable frequency refrigerator after a temperature sensor failure, as described in claim 5, is characterized in that: The calculation of the total cooling capacity of each room over a 72-hour rolling period specifically includes: Total refrigeration capacity Total cooling capacity for variable temperature Total refrigeration capacity 7. The temperature control method for a variable frequency refrigerator after a temperature sensor failure according to claim 6, characterized in that: The total runtime of the calculation 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 calculation of the average cooling power of each room specifically includes: Total refrigeration capacity P ld =Q ld ÷T total ; Total cooling capacity P for variable temperature bw =Q bw ÷T total ; Total refrigeration capacity P lc =Q lc ÷T total .

9. The temperature control method for a variable frequency refrigerator after a temperature sensor failure, as described in claim 8, is characterized in that: The preset compressor target start-up rate range, compressor default speed, and start-up / stop cycle are defined, and the required start-up time for each room is calculated, specifically including: Preset the compressor target uptime range η0, compressor default speed s0, and start-stop cycle T; Calculate the required startup time for each room: Freezer start-up time Variable temperature start-up time Refrigeration start-up time 10. The temperature control method for a variable frequency refrigerator after a temperature sensor failure according to claim 9, characterized in that: The step of calculating the start-up rate based on the required start-up time of each room to obtain the final compressor speed specifically includes: If η>η0, the default speed will be increased by one gear, and the calculation of start-up time allocation will be carried out again in S6 and S7, and the start-up rate will be checked again until the start-up rate is satisfied. At this time, the speed is s. If it is still not satisfied after increasing to the highest gear, the highest gear will be executed. If η < η0, the default speed will be reduced by one level, and the calculation of start-up time allocation will be repeated in S5 and S6, and the start-up rate will be checked again until the start-up rate is satisfied. At this time, the speed is s. If the speed is reduced to the lowest level and the requirement is still not met, the lowest level will be used.

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