A sterilization control method for air-cooled refrigerators

Abstract

This invention discloses a sterilization control method for a frost-free refrigerator. The electronic control device controls the working state and duration of the sterilization device according to the following three rules: rule one is to avoid wasting electrical energy; rule two is to perform initial sterilization with a suitable quantity of items for powerful sterilization; and rule three is to perform routine sterilization during normal refrigerator operation. These rules reflect the applicant's technical approach of simplifying bacterial sources and demonstrate the applicant's new understanding of the factors affecting bacterial content in the refrigerator's air. Using this invention, sterilization is effectively achieved in both the initial power-on and continuous operation states to ensure no harm to the health of food inside the refrigerator and the user, with good sterilization results. Simultaneously, it avoids excessively long sterilization times and ineffective sterilization that would waste electrical energy, and the sterilization device's lifespan is extended by preventing it from operating for too long.

Description

Technical Field

[0001] This invention relates to the field of refrigerator sterilization technology, and more particularly to refrigerator sterilization and energy-saving technology. Background Technology

[0002] As people's living standards continue to improve, refrigerators have become a common household item. However, many people's incorrect usage habits often turn refrigerators into "bacteria boxes" (the air inside the refrigerator contains excessively high levels of bacteria), which not only fails to preserve food but can also negatively impact people's health. Therefore, antibacterial refrigerators have emerged.

[0003] Currently, the sterilization refrigerators on the market use sterilization devices that operate in a fixed mode, which sometimes results in incomplete sterilization and sometimes ineffective sterilization when it is not needed. This not only leads to higher overall energy consumption for the refrigerator, but also sometimes the incomplete sterilization can endanger the health of users.

[0004] Detecting airborne bacteria requires specialized equipment, which is too costly and unsuitable for use in household refrigerators. The applicant aims to solve the problem of how to make a sterilization device work in accordance with the bacterial levels inside the refrigerator at a lower cost.

[0005] The applicant has studied this issue in depth.

[0006] There are two sources of bacteria in a refrigerator: 1. Bacteria that enter the refrigerator through the exchange of air between the inside and outside when the door is opened and closed. 2. Bacteria that multiply naturally inside the refrigerator.

[0007] The applicant's initial technical approach was naturally to consider both sources of bacteria, because neglecting either would render effective sterilization impossible. However, further research revealed that the natural proliferation of bacteria within the refrigerator requires consideration of numerous factors, such as the type and quantity of food, the surface area of ​​food exposed to air, the placement and stacking of food, the types of bacteria, and the set temperature. These numerous factors make monitoring the natural proliferation of bacteria excessively costly, potentially driving up the price of a refrigerator beyond consumer expectations.

[0008] The main task of this invention is to eliminate the health threats posed by two sources of bacteria in the air inside the refrigerator at a lower cost using a simplified technical approach. Summary of the Invention

[0009] The purpose of this invention is to provide a sterilization control method for air-cooled refrigerators, so as to make the operation of the sterilization device match the bacterial content in the refrigerator at a lower cost.

[0010] To achieve the above objectives, the present invention provides a sterilization control method for a frost-free refrigerator. The refrigerator has an electronic control device, which is connected to a door control switch for the refrigerator compartment, a fan for generating circulating air inside the refrigerator, a refrigerator air door for controlling whether the circulating air passes through the refrigerator compartment, and a sterilization device for sterilizing the circulating air.

[0011] The sterilization control method for the air-cooled refrigerator of the present invention is carried out according to the following rules:

[0012] Rule number one is the rule to avoid wasting electricity;

[0013] Rule 2 is the rule for initial power-on sterilization to match the quantity of items for powerful sterilization;

[0014] Rule 3 is the routine sterilization rule when the refrigerator is working normally.

[0015] Rule 1 specifically states that when the refrigeration door is closed, the electronic control device should keep the sterilization device in the off state to avoid wasting electrical energy.

[0016] Rule Two specifically states: Within 2 hours of the refrigerator being first powered on:

[0017] Before the sterilization device has accumulated 50 minutes of operation, as long as the refrigerator door is opened, the electronic control device will keep the sterilization device in operation. The electronic control device will also keep track of the cumulative operating time and cumulative off time of the sterilization device. After the sterilization device has accumulated 50 minutes of operation, the electronic control device will keep the sterilization device in off state until the cumulative time of the sterilization device in off state also reaches 50 minutes. Then, as long as the refrigerator door is opened, the electronic control device will keep the sterilization device in operation until the refrigerator's initial power-on time reaches 2 hours.

[0018] Rule 3 specifically states: If the refrigerator is powered on for more than 2 hours initially:

[0019] The electrical control device controls the working status of the sterilization device in a 4-hour control cycle.

[0020] Within one control cycle, the cumulative working time of the electrically controlled sterilization device is T minutes, where T = 0.5 × t. 0.5 ×m×25+30; where t is the door opening time in minutes, rounded to the nearest integer with a maximum value of 4, and the initial value within one control cycle is 0; m is the number of times the refrigerator door is opened, rounded to the nearest integer, and the initial value within one control cycle is 0; within one control cycle, the value of m increases by 1 each time the electronic control device receives a door control switch signal, until m=10 and then stops increasing.

[0021] The applicant's final technical approach is to simplify the two sources of bacteria into one. How to simplify it? First, when the refrigerator is first powered on, a prolonged and powerful sterilization process will kill any existing bacteria inside. While it's impossible to kill them all, as long as a powerful sterilization is performed again before the low bacterial count naturally multiplies to a level that poses a health hazard, there's no need to consider the issue of bacteria naturally multiplying and increasing the bacterial content in the air inside the refrigerator. Refrigerators are frequently used appliances; even if users don't use them for all three meals a day, they usually use them twice a day, morning and evening. Even if they don't use them for cooking, they may use them to store fruits, drinks, etc. Every time the refrigerator is used, the door is opened and closed, causing gas exchange between the inside and outside, allowing bacteria from the outside air to enter the refrigerator. The more frequently the door is opened, the greater the impact of external bacteria on the bacterial content in the air inside the refrigerator. The more frequently the door is opened and closed, the more items may be placed inside the refrigerator, further increasing the bacterial content in the air inside.

[0022] Through divergent thinking and comprehensive consideration, the applicant simplified the process, no longer focusing on the natural increase in bacteria inside the refrigerator. Instead, by using a powerful initial sterilization upon power-up, and then matching the operation of the sterilization device to the opening and closing of the door (after the initial powerful sterilization, the bacterial content in the air inside the refrigerator does not increase to a level exceeding the bacterial content in the air outside the refrigerator in most household use scenarios, so the sterilization device can naturally solve the risk of bacterial overproduction), the applicant eliminated the health threats posed by two sources of bacteria in the refrigerator's air at extremely low cost (mainly the cost of designing the control program). This solved the technical problem of matching the sterilization device's operation to the bacterial content inside the refrigerator with the refrigerator's cost, improving refrigerator quality and possessing significant value for widespread application.

[0023] Using this invention, there is no need to detect the bacterial content in the circulating air inside the frost-free refrigerator. The sterilization device of the refrigerator can be matched with the bacterial content in the circulating air inside the refrigerator. This can prevent excessive bacteria in the refrigerator from harming the food inside and the health of the user, and also prevent the sterilization device from performing ineffective sterilization when sterilization is not required, thereby reducing the energy consumption of the refrigerator.

[0024] Rule 1 is because when the air is not circulating, the bacterial content near the sterilization device will decrease rapidly, and the sterilization device cannot effectively sterilize the air circulating inside the box even if it continues to work.

[0025] Rule Two stipulates that after the refrigerator is first powered on, the sterilization period can reach 70 minutes within 2 hours (after initial power-on, the refrigerator compartment temperature is high, so the refrigerator door is open for a longer time), thus performing powerful sterilization. If the refrigerator door is open for less than 70 minutes after the refrigerator is first powered on, it means that fewer items were initially placed in the refrigerator; the fewer items initially placed in the refrigerator, the lower the impact of bacteria on the surface of the items on the bacterial content in the air inside the refrigerator, and the less sterilization time is required. Therefore, Rule Two combines powerful sterilization (when more items are placed in the refrigerator, the sterilization time will naturally reach 70 minutes) with energy saving (when fewer items are placed in the refrigerator, the refrigerator door opening time will be shorter, thus automatically shortening the working time of the sterilization device).

[0026] Rule 3 includes the following unique technical considerations for the applicant:

[0027] As the number of times the door is opened increases, the exchange of air between the inside and outside of the refrigerator, as well as the bacteria on the surface of newly placed items, will increase the bacterial content in the air inside the refrigerator. Therefore, the more times the door is opened, the longer the sterilization device should work.

[0028] If the door is opened too many times, reaching 10 times, the air exchange between the inside and outside of the refrigerator becomes too thorough. At this point, even opening and closing the door more frequently won't significantly affect the bacterial content inside the refrigerator. It's like being in the rain without an umbrella; the longer you stay in the rain, the wetter your clothes become, but once they're soaked, further exposure won't make them even wetter. Therefore, m=10 and doesn't increase further; the maximum value is 10, ensuring a better match between the sterilization device's operating time and the number of door openings on the impact on bacteria inside the refrigerator. The principle is easy to understand, but it requires thought; easy to understand doesn't mean you can actually think of it.

[0029] If the door is open for too long, reaching 4 minutes, further extension will not have a significant impact. Therefore, similar to the number of times the door is opened, the maximum value for the t-value is set to 4 minutes.

[0030] Rule 3 reflects the above-mentioned technical considerations, which makes the working time of the sterilization device more matched with the number of times and duration of door openings after the refrigerator is powered on for more than 2 hours. This ensures that sterilization is sufficient to ensure that the health of the food inside the refrigerator and the user is not harmed, while avoiding excessive sterilization time and ineffective sterilization that would waste electricity.

[0031] Actual testing showed that the control method of this invention can ensure good sterilization effect (sterilization rate greater than 90%) in all stages of refrigerator operation.

[0032] The three rules in this invention embody the applicant's technical approach of simplifying bacterial sources and reflect the applicant's new understanding of the factors influencing bacterial content in refrigerator air. This new understanding is easily understood and is therefore novel. Without this new understanding, those skilled in the art could not have derived the three rules of this invention.

[0033] Overall, this invention ensures that the sterilization device operates in accordance with the bacterial content inside the refrigerator in both the initial power-on and continuous operation states, effectively sterilizing to ensure that the health of the food inside the refrigerator and the user is not harmed, and achieving good sterilization results. At the same time, it avoids excessively long sterilization time and ineffective sterilization that would waste energy. The sterilization device does not work for too long, which also extends its service life. Detailed Implementation

[0034] This invention provides a sterilization control method for a frost-free refrigerator. The refrigerator has an electronic control device (such as a PLC or microcontroller), which is connected to a door switch for the refrigerator compartment, a fan for generating circulating air inside the refrigerator, a refrigerator air damper for controlling whether the circulating air passes through the refrigerator compartment, and a sterilization device for sterilizing the circulating air. The sterilization device preferably uses an ultraviolet lamp, a nano-titanium dioxide mesh, and a negative ion generator, and is usually located in the refrigerator compartment. The sterilization device is a conventional technology and will not be described in detail.

[0035] Its characteristics are as follows:

[0036] Rule 1: When the refrigerator door is closed, the electronic control device will keep the sterilization device off to avoid wasting energy; (Rule 1 is because when the air is not circulating, the bacterial content near the sterilization device will decrease rapidly, and even if the sterilization device continues to work at this time, it cannot effectively sterilize the air circulating inside the refrigerator;)

[0037] Rule 2: Within 2 hours of the refrigerator being first powered on (including 2 hours):

[0038] Before the sterilization device has accumulated 50 minutes of operation, as long as the refrigerator door is open (the refrigerator door and fan will be open when the refrigerator compartment temperature is below the set range; this is the standard control method for frost-free refrigerators and will not be elaborated upon), the electronic control device will keep the sterilization device in operation. The electronic control device will also record the cumulative operating time and cumulative off-time of the sterilization device. After the sterilization device has accumulated 50 minutes of operation, the electronic control device will stop the sterilization device until the cumulative off-time also reaches 50 minutes. Then, whenever the refrigerator door is opened, the electronic control device will keep the sterilization device in operation until the refrigerator's initial power-on time reaches 2 hours.

[0039] Rule Two stipulates that after the refrigerator is initially powered on, it will perform a sterilization process for up to 70 minutes within the first 2 hours (due to the higher initial temperature in the refrigerator compartment upon initial power-on, the refrigerator door will be open for a longer period), thus providing powerful sterilization. If the refrigerator door is open for less than 70 minutes after initial power-on, it means that fewer items were initially placed in the refrigerator; the fewer items initially placed in the refrigerator, the lower the impact of bacteria on the surface of the items on the bacterial content in the air inside the refrigerator, and the less sterilization time is required. Therefore, Rule Two combines powerful sterilization (when more items are placed in the refrigerator, the sterilization time will naturally reach 70 minutes) with energy saving (when fewer items are placed in the refrigerator, the refrigerator door opening time will be shorter, thus automatically shortening the working time of the sterilization device).

[0040] Rule 3: If the refrigerator is powered on for more than 2 hours (excluding 2 hours) for the first time:

[0041] The electrical control device controls the working status of the sterilization device in a 4-hour control cycle.

[0042] Within one control cycle, the cumulative working time of the electrically controlled sterilization device is T minutes, where T (minutes) = 0.5 × t 0.5 ×m×25+30; where t is the door opening time in minutes, rounded to the nearest integer with a maximum value of 4 (i.e., after the door has been open for a cumulative period of 3.5 minutes, the value of t is always 4; the value of t has five possible values ​​from 0 to 4), and the initial value within one control cycle is 0; m is the number of times the refrigerator door is opened, rounded to the nearest integer, and the initial value within one control cycle is 0; within one control cycle, the value of m increases by 1 each time the electronic control device receives a door control switch signal, until m=10 and then stops increasing.

[0043] Rule number one is the rule to avoid wasting electricity;

[0044] Rule 2 is the rule for initial power-on sterilization to match the quantity of items for powerful sterilization;

[0045] Rule 3 is the routine sterilization rule when the refrigerator is working normally.

[0046] Rule 3 includes the following unique technical considerations for the applicant:

[0047] As the number of times the door is opened increases, the exchange of air between the inside and outside of the refrigerator, as well as the bacteria on the surface of newly placed items, will increase the bacterial content in the air inside the refrigerator. Therefore, the more times the door is opened, the longer the sterilization device should work.

[0048] If the door is opened too many times, reaching 10 times, the air exchange between the inside and outside of the refrigerator becomes too thorough. At this point, even opening and closing the door more frequently won't significantly affect the bacterial content inside the refrigerator. It's like being in the rain without an umbrella; the longer you stay in the rain, the wetter your clothes become, but once they're soaked, further exposure won't make them even wetter. Therefore, m=10 and doesn't increase further; the maximum value is 10, ensuring a better match between the sterilization device's operating time and the number of door openings on the impact on bacteria inside the refrigerator. The principle is easy to understand, but it requires thought; easy to understand doesn't mean you can actually think of it.

[0049] If the door is open for too long, reaching 4 minutes, further extension will not have a significant impact. Therefore, similar to the number of times the door is opened, the maximum value for the t-value is set to 4 minutes.

[0050] Rule 3 reflects the above-mentioned technical considerations, which makes the working time of the sterilization device more matched with the number of times and duration of door openings after the refrigerator is powered on for more than 2 hours. This ensures that sterilization is sufficient to ensure that the health of the food inside the refrigerator and the user is not harmed, while avoiding excessive sterilization time and ineffective sterilization that would waste electricity.

[0051] Actual testing showed that the control method of this invention can ensure good sterilization effect (sterilization rate greater than 90%) in all stages of refrigerator operation.

[0052] Overall, this invention can effectively sterilize in both the initial power-on and continuous operation states of the refrigerator to ensure that the health of the food inside the refrigerator and the user is not harmed, and the sterilization effect is good. At the same time, it avoids excessive sterilization time and ineffective sterilization that would waste electricity. The sterilization device will not work for too long, which also extends its service life.

[0053] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for sterilization control of a frost-free refrigerator, the refrigerator having an electronic control device, the electronic control device being connected to a door control switch for the refrigerator compartment, a fan for generating circulating air in the refrigerator, a refrigerator air door for controlling whether the circulating air passes through the refrigerator compartment, and a sterilization device for sterilizing the circulating air. Its features Follow these rules: Rule number one is the rule to avoid wasting electricity; Rule 2 is the rule for initial power-on sterilization to match the quantity of items for powerful sterilization; Rule 3 is the routine sterilization procedure when the refrigerator is working properly; Rule three specifically includes the following steps: The refrigerator's initial power-on time exceeding 2 hours is divided into multiple preset duration control cycles. Within each control cycle, the cumulative operating time T of the sterilization device is determined based on the refrigerator compartment's open state. The control cycle duration is 4 hours, and the cumulative operating time T is determined using the following formula: T = 0.5 × t 0.5 ×m×25+30; where t is the duration of a single door opening in minutes, rounded to the nearest integer with a maximum value of 4, and the initial value within a control cycle is 0; m is the number of times the refrigerator door is opened, rounded to the nearest integer with a maximum value of 10, and the initial value within a control cycle is 0; the electronic control device is configured such that: within each control cycle, each time a door switch opening signal is detected, the value of m is incremented by 1 until m reaches the upper limit of 10 times.

2. The sterilization control method for a frost-free refrigerator according to claim 1, characterized in that: Rule 1 specifically states that when the refrigeration door is closed, the electronic control device should keep the sterilization device in the off state to avoid wasting electrical energy. Rule Two specifically states: Within 2 hours of the refrigerator being first powered on: Before the sterilization device has accumulated 50 minutes of operation, as long as the refrigeration air door is opened, the electronic control device will control the sterilization device to be in working state. The electronic control device will also count the cumulative working time and cumulative stopping time of the sterilization device. After the sterilization device has accumulated 50 minutes of operation, the electronic control device will control the sterilization device to stop working until the cumulative time of the sterilization device stopping working also reaches 50 minutes. Then, as soon as the refrigerator door is opened, the electronic control device will control the sterilization device to work until the refrigerator is powered on for 2 hours. Rule 3 also includes: applicable to refrigerators that have been powered on for more than 2 hours at the time of initial power-on.