KR-20260063964-A - Defrosting cycle determination method based on the temperature difference between the evaporator and the inlet and outlet, and defrosting system using it

Abstract

The present invention relates to a method for determining a defrosting cycle based on the temperature difference between the inlet and outlet of an evaporator and a defrosting system utilizing the same, wherein the temperature difference between the inlet and outlet of the evaporator is detected according to the amount of frost formed on the evaporator fins of a freezer or refrigerator to determine an efficient defrosting cycle. The defrosting system of the present invention is configured such that temperature sensors are attached to the front and rear ends of the evaporator, respectively, to measure the temperature difference between the inlet and outlet of the evaporator that changes according to the amount of frost formed on the evaporator fins; when the temperature difference exceeds a normal temperature deviation, a defrosting heater is driven to remove the frost, and power to the defrosting heater is cut off when the set time is completed. Accordingly, the present invention enables more efficient and stable defrosting and provides the effect of saving energy and extending the lifespan of the heater rod.

Inventors

• 오진현

Assignees

• 주식회사 국제커머스그룹

Dates

Publication Date

20260507

Application Date

20241031

Claims (1)

1. (1) A step of installing temperature sensors at the inlet and outlet of the evaporator to detect the inlet temperature and outlet temperature of the evaporator; and (2) A method for determining a defrosting cycle based on the difference between the inlet and outlet temperatures of an evaporator, comprising the step of comparing the difference between the inlet and outlet temperatures of the evaporator detected above with a preset temperature deviation and determining the defrosting cycle based on the result of the comparison.

Description

Defrosting cycle determination method based on the temperature difference between the evaporator inlet and outlet, and defrosting system using the same The present invention relates to a defrosting system for a freezer or refrigerator, and more specifically, to a method for determining a defrosting cycle based on the temperature difference between the inlet and outlet of an evaporator, which detects the temperature difference between the inlet and outlet of an evaporator that changes according to the amount of frost formed on the fins of the evaporator, thereby determining an effective defrosting cycle and enabling defrosting accordingly, and a defrosting system using the same. Generally, a refrigerated or frozen warehouse is a place where food is stored in a refrigerated or frozen state to prevent spoilage, and a low temperature must be maintained to preserve the quality of the stored goods. Refrigeration or freezing systems applied to such cold storage warehouses need to enable even refrigeration or freezing of a relatively large space, and additionally, are required to maintain the storage temperature evenly within a set temperature range. In such a refrigeration or freezing system, the refrigerant is circulated by a compressor inside the piping, and as the liquid refrigerant expands at the expansion valve and flows through the evaporator, air is passed between the evaporator fins by a fan. The refrigerant, which is vaporized by heat exchange, is drawn into the compressor, and the cooled air is evenly distributed throughout the cold storage or freezing warehouse, thereby refrigerating or freezing. During this process, moisture contained in the air passes through the evaporator fins, causing frost to adhere to the pipes and fins, which blocks the flow of air and prevents proper refrigeration or freezing. To solve this, a defrosting operation is performed to remove frost attached to the evaporator fins. Various defrosting methods have been proposed, including natural defrosting, which involves stopping the operation of the refrigeration unit for a certain period; hot gas defrosting, which involves introducing hot gas to melt the material; electric defrosting, which involves installing an electric heater on the evaporator and supplying electricity at regular intervals; and spray defrosting, which removes material by spraying water. The defrosting method currently in general use is a method that uses a timer to drive a heater built into the evaporator at regular intervals, regardless of frost buildup, to perform defrosting. Typically, a timer-based defrosting system is operated for 20 to 30 minutes every 4 to 6 hours, regardless of whether frost has formed. However, the aforementioned conventional defrosting method using a timer had the following problems. Since it operates regardless of whether frost is attached, defrosting may not be done properly depending on changes in temperature, or the operating time of the defrost heater must be adjusted according to the temperature or the number of times the refrigerator or freezer door is opened and closed, which is very unreasonable. Also, if the defrost time interval is set too short, the refrigeration unit must be additionally operated to cool the heat generated by the heater and the electrical energy lost when the heater is running, so not only is there severe loss of electrical energy, but frequent operation of the heater also shortens the lifespan of the heater, requiring the heater to be replaced frequently. To address the above problems, there is a method to operate a defrosting system by detecting the presence or absence of frost based on the wind pressure, utilizing the principle that when frost adheres to the air generated by the fan motor as it passes through the evaporator, the amount and intensity of the air passing between the fins decrease, thereby weakening the wind pressure. However, the aforementioned conventional defrosting method using air pressure is primarily applied to household refrigerators and is not suitable for industrial, food, or refrigerated or frozen warehouses storing agricultural and marine products. Furthermore, implementing this method entails the inconvenience of having to disassemble and reprocess existing components such as evaporators, while the configuration of the air pressure detection system is complex. Additionally, since air pressure undergoes subtle changes depending on the opening and closing of the warehouse door or the volume of contents inside, there is a possibility of malfunction. FIG. 1 is a perspective view showing a defrosting system to which the present invention is applied. FIG. 2 is a side cross-sectional view showing the state in which temperature sensors are installed at the inlet and outlet of the evaporator, Figures 3 (a) and (b) are cross-sectional views of the piping to illustrate the attachment locations of temperature sensors at the evaporator inlet and outlet. Terms and words used in this specific