A control method for intelligent frost of air-cooled refrigeration equipment

Abstract

The present invention discloses an intelligent frost control method for air-cooled refrigeration equipment, comprising the following steps: monitoring the evaporator temperature and the internal temperature of a storage cabinet of the equipment using a sensor, obtaining a difference Q between the evaporator temperature and the internal temperature of the cabinet, and adjusting the defrost mode activation interval and / or the duration of each defrost mode activation and / or the defrost stop temperature at which defrosting is stopped in the defrost mode according to a system preset value based on the obtained difference Q. The present invention can reduce or avoid frost or ice blockage of the evaporator and save energy.

Description

Technical Field

[0001] The invention relates to a method for controlling intelligent frost of air-cooled refrigeration equipment. Background Art

[0002] Common air-cooled refrigeration equipment includes refrigerators and freezers. Air-cooled refrigeration equipment actively controls air circulation through fans. The circulating air continuously exchanges heat with the evaporator, which then indirectly cools the cabinet or room through air ducts. Frost primarily condenses on the evaporator, necessitating defrosting.

[0003] There are generally two existing defrosting methods:

[0004] The first method uses an electric heating tube to defrost the evaporator. The heating tube is inserted into the middle or lower part of the evaporator. The second method uses a compressor heat pump to defrost. The high-pressure pipe of the compressor bypasses the high-temperature and high-pressure refrigerant discharged from the condenser and discharges it to the evaporator at the same time, using the high-temperature and high-pressure refrigerant to defrost the evaporator.

[0005] The above two defrosting methods generally implement fixed defrosting modes by setting parameters such as the defrost interval (i.e., the start interval of the defrost mode), the defrost end temperature (i.e., the defrost stop temperature value at which defrost stops in the defrost mode), the defrost duration (i.e., the duration of each defrost mode start), and the air volume adjustment. In actual applications, the following problems exist:

[0006] 1. When the ambient temperature fluctuates significantly, or the operating ambient temperature differs significantly from the factory test ambient temperature, since the defrost mode is fixed, when the ambient temperature changes from low to high, the refrigeration system's thermal cycle capacity decreases, the condensing temperature increases, and the cooling capacity decreases. If the set defrost interval is lower than the cooling cycle, defrosting will occur before the temperature inside the refrigerator or freezer can reach a low temperature, which will increase the cabinet temperature and significantly waste energy. When the ambient temperature changes from high to low, the condenser temperature decreases, the compressor's thermal cycle capacity increases, and the cooling capacity increases. If the same defrost cycle interval as when the ambient temperature is high is still used, the evaporator will remain in a low temperature state for a long time, causing frost accumulation, which in turn may cause frost or ice blockage during the defrost cycle.

[0007] 2. When the ambient humidity fluctuates significantly, or differs significantly from the factory-tested humidity, such as when the dry climate of winter changes to rainy weather in spring, the humidity may rise from 30% to 90% within 24 hours. This increased humidity can cause air to enter the refrigerator or freezer when the door is opened to take out or store items. This high-humidity air enters the air-cooled air circulation system, significantly increasing the amount of frost and ice formed on the low-temperature evaporator. This significantly increases the probability of ice or frost blockage on the evaporator. If the control system continues to execute the original fixed defrost cycle, there is a high probability of incomplete defrosting of the evaporator, resulting in frost or ice blockage, and the temperature inside the refrigerator or freezer will not meet the specified value. Conversely, if the defrost cycle is adjusted for high-humidity operating environments, the set defrost cycle will be shortened when the ambient humidity decreases, resulting in increased energy consumption due to frequent defrosting.

[0008] 3. When usage frequency changes, that is, when the frequency of opening the refrigerator or freezer to store or retrieve items changes. Existing air-cooled refrigeration equipment is generally equipped with a door switch. The difference in door opening frequency between peak business hours and evening hours is significant. When the door is closed at night, the refrigerator or freezer does not receive as much air, reducing the load. Using the same defrost cycle as during daytime hours will increase defrost frequency and energy consumption. Conversely, setting the defrost cycle for low nighttime usage will result in frost or ice blockage during daytime hours.

[0009] 4. When the door seals, card strips, door frames, door hinges and other consumable parts of the refrigerator or freezer are damaged, outside air will continue to enter the refrigerator or freezer, increasing the load of the refrigeration system and the moisture content in the air circulation, causing frost and ice on the evaporator. In severe cases, it will lead to frost on the air inlet and exhaust vents. At the same time, when the condenser is dirty and blocked, the system heat exchange rate decreases, the cooling capacity decreases, and the frost and ice conditions of the evaporator will also change accordingly.

[0010] 5. When a refrigerator or freezer is used abnormally, such as due to high traffic volume or competitive factors, large quantities of goods may need to be purchased in advance during peak business hours. This can cause severe blockage inside the refrigerator or freezer, resulting in poor internal air circulation and causing frost and ice to form on the evaporator. This can ultimately lead to a rise in temperature inside the cabinet and food spoilage.

[0011] In summary, through long-term laboratory testing and verification and observation in market business premises, the following regular phenomena were discovered: when there are changes in ambient temperature, humidity, frequent door opening, damaged door seals, and objects blocking the cabinet, the evaporator will often be frosted and iced, causing the temperature inside the cabinet to cool down slower, the temperature inside the cabinet to rise, or energy consumption to increase. Summary of the Invention

[0012] The object of the present invention is to provide an intelligent frost control method for air-cooled refrigeration equipment, which can reduce or avoid frost blockage or ice blockage of the evaporator and save energy.

[0013] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0014] A method for controlling intelligent frost of an air-cooled refrigeration device comprises monitoring the evaporator temperature value of the refrigeration device and the internal temperature value of a cabinet used for storage of the refrigeration device through a sensor, obtaining a difference Q between the evaporator temperature value and the internal temperature value of the cabinet, and automatically adjusting the start interval time of a defrost mode and / or the duration of each start of the defrost mode and / or the defrost stop temperature value for stopping defrosting in the defrost mode according to the size of the obtained difference Q corresponding to the system preset value of the refrigeration device.

[0015] When the ambient temperature drops, the humidity increases, the door is opened frequently, the door seal is damaged, or items in the cabinet become clogged, the evaporator often forms frost and ice significantly, resulting in a decrease in the amount of air circulating through the evaporator, a significant drop in the evaporator temperature, and a slower cooling or temperature rise inside the cabinet, increasing the difference between the evaporator temperature and the cabinet's internal temperature. The present invention intelligently adjusts the defrost capacity of an air-cooled refrigeration device based on the difference between the evaporator temperature and the cabinet's internal temperature. This solves the problem of insufficient defrost capacity in the prior art, reduces or prevents frost or ice blockage in the evaporator, and addresses the problem of frequent defrosting and the need for repeated refrigeration in the prior art, saving energy.

[0016] The present invention also has the following preferred design:

[0017] The system preset value corresponding to the difference Q of the refrigeration equipment of the present invention includes the following intervals:

[0018] a: -5℃<Q≤-2℃,

[0019] b: -10℃<Q≤-5℃,

[0020] c: -15℃<Q≤-10℃,

[0021] d: -20℃<Q≤-15℃,

[0022] e: -25℃<Q≤-20℃,

[0023] f: -30℃<Q≤-25℃,

[0024] g: Q≤-30℃,

[0025] According to the obtained difference Q, the system preset intervals a, b, c, d, e, f and g of the refrigeration equipment are automatically adjusted to automatically adjust the start interval time of the defrost mode and / or automatically adjust the duration of each start of the defrost mode and / or automatically adjust the defrost stop temperature value for stopping defrost in the defrost mode.

[0026] Because the operating environment of the equipment varies greatly, such as ambient temperature, humidity, frequency of use, and the inherent defrosting ability of the equipment, the above range values ​​can be set according to the operating environment of the equipment and equipment usage experience.

[0027] In the present invention, when the difference Q obtained before the defrost mode is started N times consecutively is located in any same interval among intervals a, b, c, d, e, f and g for N times consecutively, the start interval of the defrost mode and / or the duration of each start of the defrost mode and / or the defrost stop temperature value for stopping defrosting in the defrost mode are automatically adjusted again, wherein N ≥ 2;

[0028] For example, before starting the defrost mode for three consecutive times, the difference Q is ≤-20℃, which means that the evaporator has been severely frosted from the first two consecutive defrosts to the third defrost, and the defrost capacity is insufficient. In this case, the defrost capacity should be improved, the start interval of the defrost mode should be reduced, or the duration of each defrost mode start-up should be extended, or the defrost stop temperature value should be increased.

[0029] When the refrigeration device of the present invention is in cooling mode, if the difference Q is less than a system preset value Q1 for a period of time T1, the defrost mode is immediately activated. For example, if the difference Q is less than -30°C for 10 minutes before the defrost mode is activated, it is determined that the evaporator is severely ice-blocked, and the defrost mode can be immediately activated to defrost and resolve the ice blockage.

[0030] After a defrost mode of the refrigeration equipment of the present invention ends, before the next defrost mode is started, if the difference Q is continuously less than the system preset value Q2 of the refrigeration equipment for a period of time T2, it indicates that the defrost capacity is insufficient, and the duration of the next defrost mode is increased.

[0031] When the difference Q of the present invention is less than or equal to a preset alarm value of the refrigeration system, an alarm signal is issued to remind personnel to eliminate the abnormality.

[0032] The present invention has the following beneficial effects:

[0033] The defrosting method of the present invention determines abnormalities in the defrosting capacity of the equipment based on the difference between the evaporator temperature and the internal temperature of the cabinet, thereby automatically adjusting the defrosting mode of the equipment. This method can solve the problem of frost or ice blockage of the evaporator caused by environmental temperature and humidity, frequency of use, door seal effectiveness, and abnormal use, and can also avoid energy waste caused by too frequent defrosting. The present invention can intelligently and automatically adjust the defrosting mode based on the real-time operating status of the air-cooled refrigeration equipment, which is of great significance for improving the temperature control level of the equipment and reducing energy consumption. DETAILED DESCRIPTION

[0034] The technical solutions of the present invention are described in detail below in conjunction with embodiments so that those skilled in the art can better understand and implement the technical solutions of the present invention.

[0035] A method for controlling intelligent frost of an air-cooled refrigeration device comprises monitoring the evaporator temperature value of the refrigeration device and the internal temperature value of a cabinet used for storage of the refrigeration device through a sensor, obtaining a difference Q between the evaporator temperature value and the internal temperature value of the cabinet, and automatically adjusting the start interval time of a defrost mode and / or the duration of each start of the defrost mode and / or the defrost stop temperature value for stopping defrosting in the defrost mode according to the size of the obtained difference Q corresponding to the system preset value of the refrigeration device.

[0036] As a preferred embodiment:

[0037] The system preset value of the refrigeration equipment corresponding to the difference Q includes the following ranges:

[0038] a: -5℃<Q≤-2℃,

[0039] b: -10℃<Q≤-5℃,

[0040] c: -15℃<Q≤-10℃,

[0041] d: -20℃<Q≤-15℃,

[0042] e: -25℃<Q≤-20℃,

[0043] f: -30℃<Q≤-25℃,

[0044] g: Q≤-30℃,

[0045] According to the obtained difference Q, the system preset interval a, interval b, interval c, interval d, interval e, interval f and interval g of the refrigeration equipment corresponding to the automatically adjusted start interval time of the defrost mode and / or the automatically adjusted duration time of each start of the defrost mode and / or the automatically adjusted defrost stop temperature value for stopping defrost in the defrost mode can be realized by a programmable program.

[0046] For example, when the difference Q falls within the interval a: -5°C < Q ≤ -2°C, it indicates that the equipment: the cooling air circulation is good, the evaporator and the cabinet circulation are smooth, and the heat exchange is smooth;

[0047] When the difference Q falls within the range b: -10℃<Q≤-5℃, it indicates that the equipment: the refrigeration air circulation is normal, and the evaporator and the cabinet circulation are in normal heat exchange state;

[0048] When the difference Q falls within the range c: -15℃<Q≤-10℃, it means that the cooling air circulation of the equipment begins to be slightly obstructed, and the evaporator and cabinet circulation are in a slightly obstructed heat exchange state;

[0049] When the difference Q falls within the range d: -20℃<Q≤-15℃, it means that the equipment: the cooling air circulation is blocked, the evaporator and the cabinet circulation are in a blocked heat exchange state, and the cooling capacity in the evaporator is not fully circulated through the air circulation;

[0050] When the difference Q falls within the interval e: -25℃<Q≤-20℃, it means that the equipment: the cooling air circulation is significantly obstructed, the evaporator and the cabinet circulation are in a significantly obstructed heat exchange state, and only a small part of the cooling capacity in the evaporator is circulated through the air;

[0051] When the difference Q falls within the range f: -30℃<Q≤-25℃, it means that the equipment: the cooling air circulation is severely obstructed, the evaporator and the cabinet circulation are in a severely obstructed heat exchange state, and only a very small part of the cooling capacity in the evaporator is circulated through the air;

[0052] When the difference Q falls within the range g: Q≤-30°C, it indicates that the equipment: the cooling air circulation is severely obstructed, the evaporator and the cabinet circulation are in a state of severely obstructed heat exchange, and only a very small part of the cooling capacity in the evaporator is circulated through the air or not at all;

[0053] Different defrost parameters can be set based on the difference Q. Because the operating environment of the equipment varies greatly, such as ambient temperature, humidity, frequency of use, and the inherent defrost capacity of the equipment, the above interval values ​​can be set based on the equipment's operating environment and experience.

[0054] When the difference Q obtained before the defrost mode is started for N consecutive times is located in any same interval among interval a, interval b, interval c, interval d, interval e, interval f and interval g for N consecutive times, the start interval time of the defrost mode and / or the duration of each start of the defrost mode and / or the defrost stop temperature value for stopping defrosting in the defrost mode are automatically adjusted again, where N ≥ 2;

[0055] For example, before starting the defrost mode for three consecutive times, the difference Q is ≤-20℃, which means that the evaporator has been severely frosted from the first two consecutive defrosts to the third defrost, and the defrost capacity is insufficient. The defrost capacity should be improved, and the start interval of the defrost mode should be reduced, or the duration of each defrost mode start should be extended, or the defrost stop temperature value should be increased.

[0056] When the refrigeration device is in cooling mode, if the difference Q is less than a system preset value Q1 for a period of time T1, the defrost mode is immediately activated. For example, if the difference Q is less than or equal to -30°C within 10 minutes before the defrost mode is activated, it is determined that the evaporator is severely ice-blocked, and the defrost mode is immediately activated to preemptively defrost, thereby reducing energy consumption and resolving the ice blockage problem.

[0057] After a defrost mode of the refrigeration equipment ends, before the next defrost mode starts, if the difference Q is smaller than the system preset value Q2 for a period of time T2, indicating that the defrost capacity is insufficient, the duration of the next defrost mode is increased.

[0058] When the difference Q is less than or equal to the alarm value preset by the system of the refrigeration equipment, an alarm signal is issued to remind personnel to eliminate the abnormality.

[0059] If the Q value before defrosting is large, it means that the evaporator has been blocked by frost or ice in the period before defrosting. If the refrigeration is continued, the refrigeration cycle effect will be poor, and the compressor, fan, etc. will continue to work, resulting in energy waste. If the Q value before defrosting is very small, it means that during the refrigeration cycle, the ice blockage or frost blockage in the evaporator is small or non-existent, and there is no need for heating and defrosting. Therefore, if defrosting is still carried out according to the original defrost cycle time, the defrosting energy consumption will increase.

[0060] The present invention can intelligently and automatically adjust the defrost mode according to the real-time working conditions of the air-cooled refrigeration equipment, which is of great significance for improving the temperature control level of the equipment and saving energy and reducing consumption.

[0061] The above embodiments are only preferred embodiments of the present invention, but they cannot be used as limitations of the invention. Any modifications and improvements based on the concept of the present invention should fall within the scope of protection of the present invention. The specific scope of protection shall be subject to the claims.

Claims

1. A method for controlling intelligent frost of air-cooled refrigeration equipment, characterized in that: The sensor monitors the evaporator temperature value in the refrigeration equipment and the internal temperature value of the cabinet used for storage of the refrigeration equipment, obtains the difference Q between the evaporator temperature value and the internal temperature value of the cabinet, and automatically adjusts the start interval time and / or the duration of each start of the defrost mode and / or the defrost stop temperature value for stopping defrost in the defrost mode according to the size of the obtained difference Q corresponding to the system preset value of the refrigeration equipment. The system preset value of the refrigeration equipment corresponding to the difference Q includes the following ranges: a: -5℃<Q≤-2℃, b: -10℃<Q≤-5℃, c: -15℃<Q≤-10℃, d: -20℃<Q≤-15℃, e: -25℃<Q≤-20℃, f: -30℃<Q≤-25℃, g: Q≤-30℃, Automatically adjust the start interval of the defrost mode and / or the duration of each start of the defrost mode and / or the defrost stop temperature value for stopping defrost in the defrost mode according to the obtained difference Q corresponding to the system preset intervals a, b, c, d, e, f and g of the refrigeration equipment; When the difference Q obtained before the defrost mode is started for N consecutive times is located in any same interval among interval a, interval b, interval c, interval d, interval e, interval f and interval g for N consecutive times, the start interval time of the defrost mode and / or the duration of each start of the defrost mode and / or the defrost stop temperature value for stopping defrost in the automatic defrost mode are automatically adjusted again, where N≥2.

2. The intelligent frost control method for air-cooled refrigeration equipment according to claim 1, characterized in that: When the refrigeration device is in the cooling mode, if the difference Q is smaller than the system preset value Q1 of the refrigeration device for a period of time T1, the defrost mode is immediately started.

3. The intelligent frost control method for air-cooled refrigeration equipment according to claim 1, characterized in that: After a defrost mode of the refrigeration device ends, before the next defrost mode starts, if the difference Q is smaller than the system preset value Q2 of the refrigeration device for a period of time T2, the duration of the next defrost mode is increased.

4. The intelligent frost control method for air-cooled refrigeration equipment according to any one of claims 1 to 3, characterized in that: When the difference Q is less than or equal to a preset alarm value of the refrigeration equipment system, an alarm signal is issued.