JP2017156077A - Defrosting device for evaporator and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting and removing frost formed on an evaporator and a method for controlling it.SOLUTION: An evaporator 10 includes: a cooling fin 12 connected to a refrigerant pipe 11 in which a refrigerant circulates and for performing heat exchange; a support bracket 13 for supporting the refrigerant pipe 11; and a defrosting heater 14 for supplying heat for removing the frost formed on the refrigerant pipe 11. A defrosting device 100 for evaporator includes: a light emitting part 120 for radiating light toward the cooling fin 12 provided at one side of the evaporator 10; a sensor part 130 for detecting the amount of light reflected at the cooling fin 12; and a control part (not shown) for controlling ON/OFF of the defrosting heater 14 based on the detected value.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an apparatus for detecting and removing frost formed on an evaporator and a method for controlling the apparatus.

  The evaporator used in the refrigeration cycle lowers the ambient temperature using cold air generated by the circulation of the refrigerant flowing through the cooling pipe. If a temperature difference from the surrounding air occurs in this process, a frosting phenomenon occurs in which moisture in the air condenses and freezes on the surface of the cooling pipe.

  For example, when the evaporator is applied to a refrigerator, air in the freezer compartment and the refrigerator compartment flows from the lower side of the evaporator and evaporates by driving a blower fan and a compressor provided at the rear of the refrigerator. Heat is exchanged with the refrigerant that passes through the evaporator and flows through the refrigerant pipe of the evaporator, and cold air is supplied to the freezer compartment or the refrigerator compartment. The air discharged from the freezer compartment and the refrigerator compartment is heat-exchanged with the refrigerant flowing through the refrigerant pipe by the cooling fins. In this process, the air flowing from the freezer compartment and the refrigerator compartment into the evaporator is cooled by the cold air passing through the evaporator. Since it is in a relatively hot and humid state, it is condensed by contact with hot and humid air in the low temperature evaporator, and frost forms on the cooling fins due to the low temperature of the refrigerant pipe.

  When frost forms on the cooling fins, the area where the air moving to the evaporator by the blower fan comes into contact with the cooling fins is reduced, so that the heat absorbed by the refrigerant flowing through the refrigerant pipe of the evaporator is reduced, and the efficiency of the evaporator There has been a problem of lowering. Therefore, although the defrost heater is driven to remove the frost that has formed frost, it may be judged that the frost has been formed even though it has not been frosted, and the defrost heater may be driven. There was a problem of bringing.

  Conventionally, in order to detect frost that has formed on the cooling fins, it is determined that frost has formed on the cooling fins when the temperature is below a predetermined temperature by providing a temperature sensor, or both the temperature sensor and humidity sensor are used. By providing, the dew point was measured and the frost which formed on the cooling fin was detected, and then the defrost heater was driven.

  However, if the humidity is low even if the temperature is lower than the specified temperature, frost may not form on the cooling fin, and it is difficult to measure the dew point accurately because the humidity sensor is difficult to measure with high accuracy. There was a problem that the driving of a defrosting heater could not be prevented.

  Therefore, there is an increasing need for a device that can detect frost formed on the cooling fins with high accuracy and prevent unnecessary driving of the defrosting heater.

  The objective of this invention is providing the apparatus which detects and removes the frost which formed frost on the cooling fin, when the refrigerant | coolant of an evaporator circulates.

  Another object of the present invention is to provide an apparatus that effectively detects and removes frost formed on the cooling fin and the amount of frost formed on the cooling fin.

  Still another object of the present invention is to provide an apparatus for effectively detecting and removing frost formed on cooling fins and the amount of frost formed on the cooling fin without restricting the flow of air by the blower fan.

  Still another object of the present invention is to provide an apparatus for transmitting a signal for operating a defrost heater in order to remove frost formed on the cooling fins.

  Still another object of the present invention is to provide an apparatus that can reduce unnecessary energy consumption by operating a defrosting heater only when frost forms on the cooling fin.

  Still another object of the present invention is to continue the frost formation and the amount of frost formation without flowing into the sensor unit and the light emitting unit even if the frost formed on the cooling fin melts due to the operation of the defrost heater. An object of the present invention is to provide a device structure capable of detection.

  To achieve the above object, an evaporator defrosting apparatus according to an embodiment of the present invention includes a cooling fin that is coupled to a refrigerant pipe through which a refrigerant flows to exchange heat, a support bracket that supports the refrigerant pipe, and In an evaporator including a defrost heater that supplies heat for removing frost formed on the refrigerant pipe, a light emitting unit that emits light toward the cooling fin provided on one side of the evaporator; The sensor part which detects the quantity of the light reflected with the said cooling fin, and the control part which controls on / off of the said defrost heater based on the said detected value are included.

  According to an aspect of the present invention, the control unit turns on the defrost heater when the amount of light detected by the sensor unit is equal to or less than a first reference value, and detects the light detected by the sensor unit. If the amount is greater than or equal to the second reference value, the defrost heater is turned off, and the first reference value is smaller than the second reference value.

  According to an aspect of the present invention, the light emitting unit emits light at a predetermined angle toward the cooling fin, and the sensor unit detects the light reflected by the cooling fin. Is provided at an angle corresponding to.

  According to an aspect of the present invention, the sensor unit includes an illuminance sensor that detects the frost and the amount of frost formed on the cooling fin by detecting the brightness of light.

  According to an aspect of the present invention, the sensor unit includes an RGB sensor that detects the color of the reflected light and detects frost formed on the cooling fin and the amount of frost formed thereon.

  According to an aspect of the present invention, the defroster for the evaporator further includes a substrate for supplying power to the light emitting unit and the sensor unit and fixing the light emitting unit and the sensor unit at a predetermined angle. Including.

  According to an aspect of the present invention, the defroster for the evaporator further includes a case that is disposed on the support bracket and disposed to face the cooling fin.

  Here, the case includes a vertical extension for fixing to the support bracket, and the cooling fin from both ends of the vertical extension so as to prevent liquid from flowing into the light emitting unit and the sensor unit. You may make it consist of a horizontal extension part which each protrudes and extends toward it.

  The horizontal extension may be formed such that one end is bent toward the center of the vertical extension.

  According to an aspect of the present invention, the defroster for the evaporator is installed on the lower side of the support bracket, and the support bracket and the cooling so as to face the cooling fin extended downward. Arranged between the fins.

  According to one aspect of the present invention, the defroster for the evaporator is installed at a plurality of locations below the support bracket.

  In order to achieve the above object, a method of controlling a defrosting device configured to include a light emitting unit and a sensor unit according to an embodiment of the present invention and attached to an evaporator includes: A first stage in which the light emitting unit emits light toward the cooling fin of the evaporator, and the sensor unit detects the amount of light reflected by the cooling fin, and the amount of light detected by the sensor unit is first. When the amount of light detected by the sensor unit by driving the defrost heater is equal to or greater than a second reference value when the defrost heater of the evaporator is turned on when the reference value is 1 reference value or less, And a third stage for turning off the defrosting heater.

  According to the present invention having such a configuration, the frost formed on the cooling fin is detected by detecting the light irradiated from the light emitting unit and reflected by the cooling fin by the sensor unit, and the frost is removed by the defrost heater. be able to.

  Further, according to the present invention having such a configuration, the light emitting unit and the sensor unit are provided at corresponding angles, and light reflected from the cooling fins irradiated with frost and irradiated from the light emitting unit is received by the sensor unit. By doing so, the frost and the amount of frost formed on the cooling fin can be detected and removed effectively.

  Furthermore, according to the present invention having such a configuration, it is determined whether or not frost has formed on the basis of the received value detected by the sensor unit, and the control unit outputs a signal for driving the defrost heater. Can be sent.

  Furthermore, according to the present invention having such a configuration, unnecessary energy consumption can be reduced by operating the defrosting heater by the control unit only when frost forms on the cooling fin.

  Furthermore, according to the present invention having such a configuration, even if the frost frosted on the cooling fin is melted by the operation of the defrosting heater, it does not flow into the sensor unit and the light emitting unit, thereby reducing false detection of frosting. Can do.

It is a conceptual diagram of the refrigerator containing a defrosting apparatus. It is a perspective view of the evaporator provided with the defrosting apparatus. It is the A section enlarged view of the evaporator of FIG. It is a longitudinal cross-sectional view of the evaporator of FIG. It is a conceptual diagram of the defrosting device of an evaporator, (a) is a figure which shows the state with which the light emission part and the sensor part were provided on the flat board | substrate, (b) is a predetermined angle between a light emission part and a sensor part. It is a figure which shows the state which was provided on the board | substrate. It is a figure which shows one Embodiment of the defrosting apparatus of an evaporator. It is a figure which shows other embodiment of the defrosting apparatus of an evaporator. It is a figure which shows other embodiment of the defrosting apparatus of an evaporator. It is a figure which shows other embodiment of the defrosting apparatus of an evaporator. It is a figure which shows the modification of the installation position of the defroster of an evaporator. It is a figure which shows the modification of the installation position of the defroster of an evaporator. It is a figure which shows the operation | movement process of the defroster of an evaporator. It is a flowchart which shows the operation | movement process of the defroster of an evaporator. It is a graph which shows the change of the value detected by an illuminance sensor, and the operation of a defrost heater according to it, a compressor, and a ventilation fan over time.

  Hereinafter, a defroster for an evaporator and a control method thereof according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  In the present specification, the same or similar components are denoted by the same or similar reference numerals even in different embodiments, and redundant description is omitted. As used herein, the singular form includes the plural form unless specifically stated otherwise.

  FIG. 1 is a conceptual diagram of a refrigerator including a defrosting device.

  The defroster 100 for an evaporator according to the present invention plays a role of detecting frost formed on the evaporator, and can be applied to various devices such as an air conditioner as well as a refrigerator as shown in FIG. It can also be applied to an air purification device. However, in this invention, the evaporator of the refrigerator 20 is made into the object for convenience of explanation.

  The refrigerator 20 is a device that stores food stored in the refrigerator cabinet 21 at a low temperature using cold air generated by a refrigeration cycle including compression, condensation, expansion, and evaporation.

  As shown in FIG. 1, the refrigerator cabinet 21 has a storage space for storing food inside. The storage space may be partitioned by a partition wall 21a and divided into a refrigerator compartment 22 and a freezer compartment 23 according to a set temperature.

  Although FIG. 1 shows a top mount type refrigerator 20 in which the freezer compartment 23 is arranged on the refrigerator compartment 22, the present invention is not limited to this. The present invention is a side-by-side type refrigerator in which the refrigerator compartment 22 and the freezer compartment 23 are arranged on the left and right sides, and a bottom freezer type in which the refrigerator compartment 22 is arranged on the freezer compartment 23. It can also be applied to refrigerators.

  A door is arranged in the refrigerator cabinet 21 so as to open and close the front opening of the refrigerator cabinet 21. In the same figure, the case where the refrigerator compartment door 22a opens and closes the front part of the refrigerator compartment 22, and the freezer compartment door 23a opens and closes the front part of the freezer compartment 23 is shown. The doors 22 a and 23 a can be configured by various types of doors such as a rotary door that is rotatably connected to the refrigerator cabinet 21 and a drawer door that is slidably connected to the refrigerator cabinet 21. The refrigerator cabinet 21 is provided with a storage unit 24 for efficiently using the storage space. The storage unit 24 includes a shelf 24a, a tray 24b, and a basket 24c. The shelf 24 a and the basket 24 c may be provided inside the refrigerator cabinet 21, and the tray 24 b may be provided inside a door connected to the refrigerator cabinet 21.

  A cooling chamber 27 provided with the evaporator 10 and the blower fan 25 is provided behind the freezing chamber 23. In the partition wall 21a, the refrigerator compartment return duct 21b that allows the air in the refrigerator compartment 22 to be sucked into and returned to the cooling chamber 27 side, and the freezer compartment that allows the air in the freezer compartment 23 to be sucked into and returned to the cooling chamber 27 side. A return duct 21c is formed. Further, behind the refrigerator compartment 22, a cold air duct 29 that communicates with the freezer compartment 23 and has a plurality of cold air outlets 29a in the front surface portion is provided.

  A machine room 28 is provided on the lower rear side of the refrigerator cabinet 21, and a compressor 26, a condenser (not shown) and the like are provided inside the machine room 28.

  In such a refrigerator 20, the air in the refrigerator compartment 22 is sucked into the cooling compartment 27 by the blower fan 25 in the cooling compartment 27 via the refrigerator compartment return duct 21b of the partition wall 21a, and exchanges heat with the evaporator 10. The process of being discharged into the refrigerating chamber 22 through the cold air discharge port 29a of the cold air duct 29 is repeatedly performed, and the air in the freezing chamber 23 is blown by the blower fan 25 of the cooling chamber 27 through the freezing chamber return duct 21c of the partition wall 21a. The process of being sucked into the cooling chamber 27 to exchange heat with the evaporator 10 and discharged into the freezing chamber 23 through the cold air discharge port 29a of the cold air duct 29 is repeated. In this process, frost forms on the surface of the evaporator 10 due to a temperature difference from the circulating air that re-inflows through the refrigerating room return duct 21b and the freezer room return duct 21c.

  The frost that has formed on the evaporator 10 is detected by the defroster 100 and is melted by the defrost heater 14 provided at the lower part of the evaporator 10 to remove the frost. The water generated when the frost frosted on the evaporator 10 is removed by the defrost heater 14, that is, the defrost water is collected in the lower part of the refrigerator cabinet 21 via the defrost water discharge pipe 21d.

  FIG. 2 is a perspective view of an evaporator provided with a defrosting device.

  As shown in FIG. 2, the evaporator 10 includes a refrigerant pipe (cooling pipe) 11, a plurality of cooling fins 12, and a plurality of support brackets 13 that support these on both sides of the refrigerant pipe 11.

  The refrigerant pipe 11 is formed by being bent so as to repeat a zigzag shape, and is filled with a refrigerant. The refrigerant pipe 11 may be configured by a combination of a horizontal pipe part and a bent pipe part. The horizontal piping part is arranged horizontally above and below and is configured to penetrate through the plurality of cooling fins 12, and the bent piping part includes an end part of an upper horizontal piping part and an end part of a lower horizontal piping part Are connected to communicate with each other. Here, the refrigerant pipe 11 may be configured by a single row, or may be configured by a plurality of rows in the front-rear direction of the evaporator 10.

  In the refrigerant pipe 11, a plurality of cooling fins 12 are arranged at a predetermined interval in the extending direction of the refrigerant pipe 11. The cooling fin 12 may be formed of a flat plate made of an aluminum material, and the refrigerant pipe 11 may be expanded in a state of being inserted into the insertion hole of the cooling fin 12 and firmly fixed to the insertion hole. Good. The plurality of support brackets 13 are respectively provided on both sides of the evaporator 10 and extend vertically in the vertical direction to support the bent end portion of the refrigerant pipe 11.

  The defrost heater 14 serves to remove frost that has formed on the evaporator 10, and is provided in the evaporator 10. The defrost heater 14 is electrically connected to a heating unit (not shown), and may be configured to receive an operation signal from a control unit (not shown) of the defrost device 100 and generate heat. Good. The controller may be configured to supply an operation signal to the heating unit when the defroster 100 detects that frost has formed on the evaporator 10.

  As shown in FIG. 2, the defrosting apparatus 100 according to the present invention may detect frost formed on the cooling fin 12 by being provided on one side of the support bracket 13.

  The air discharged from the freezer compartment 23 and the refrigerator compartment 22 is heat-exchanged with the refrigerant flowing through the refrigerant pipe 11 by the cooling fins 12. In this process, the air flowing from the freezer compartment 23 and the refrigerator compartment 22 into the evaporator 10 Since it is in a relatively hot and humid state than the cold air passing through the evaporator 10, it is condensed in contact with the hot and humid air in the low temperature evaporator 10, and mainly the cooling fins 12 due to the low temperature of the refrigerant pipe 11. Frost forms on the surface. The defrosting apparatus 100 according to the present invention can detect frost that has formed on the cooling fins 12 and drive the defrost heater 14 by the control unit, thereby removing the frost that has formed. Thereby, heat exchange between the air flowing through the evaporator 10 and the refrigerant flowing through the refrigerant pipe 11 can be performed smoothly.

  3 is an enlarged view of part A of the evaporator of FIG. 2, and FIG. 4 is a longitudinal sectional view of the evaporator of FIG.

  As shown in FIGS. 3 and 4, an evaporator defrosting apparatus 100 according to the present invention is provided on a support bracket 13 that supports a refrigerant pipe 11, and is used to detect frost formed on a cooling fin 12. 12 is arranged to face. That is, the defrosting device 100 is provided on the support bracket 13 that supports the refrigerant pipe 11 and is disposed so as to face the cooling fins 12, so that it is disposed between the support bracket 13 and the cooling fins 12. The defrosting device 100 is disposed facing the cooling fin 12 and detects frost by a method of receiving light reflected from the cooling fin 12 and reflecting the light. The defroster 100 may be provided anywhere on the support bracket 13 that supports the refrigerant pipe 11 as long as the defroster 100 is disposed to face the cooling fins 12.

  Since frost does not uniformly form on the surface of the evaporator 10, the evaporator 10 has a portion where a relatively large amount of frost adheres and a portion where a relatively small amount of frost adheres. Despite attempts to uniformly form frost as a whole, such as adjusting the arrangement interval of the cooling fins 12, evaporation occurs due to various factors such as the installation position of the evaporator 10 and the on / off cycle of the refrigerator 20. Rather than uniformly frosting on the entire surface of the vessel 10, a portion where a relatively large amount of frost adheres and a portion where a relatively small amount of frost adheres occur. Usually, a large amount of frost forms on the lower part of the evaporator 10. Therefore, it is preferable that the defrosting apparatus 100 according to the present invention is disposed at the lower portion of the support bracket 13 so as to detect frost formed on the cooling fins 12 disposed mainly at the lower portion of the evaporator 10.

  6 to 9 are conceptual diagrams of an evaporator defrosting apparatus according to the present invention.

  FIG. 6 shows an embodiment of an evaporator defroster.

  6 includes a case 110, a light emitting unit 120, a sensor unit 130, and a control unit (not shown).

  The case 110 forms the entire shape of the defrosting apparatus 100, and one side is fixed to the support bracket 13 and is disposed to face the cooling fin 12. The case 110 is formed in a shape having a space on the inner side so that the light emitting unit 120 and the sensor unit 130 can be arranged on the inner side.

  The case 110 includes a vertical extension 111 and a horizontal extension 112.

  The vertical extension 111 plays a role for fixing to the support bracket 13, and is fixed by being attached to the support bracket 13. For example, in order to fix the vertical extension 111 of the case 110 to the support bracket 13, a screwing method or an adhesive method may be used.

  The horizontal extensions 112 extend from the both ends of the vertical extension 111 toward the cooling fins 12 so as to prevent liquid from flowing into the light emitting unit 120 and the sensor unit 130. Here, both ends of the horizontal extension 112 are formed to be bent toward the center of the vertical extension 111 so that frost that melts by driving the defrosting heater 14 flows along both ends of the horizontal extension 112. May be. That is, the horizontal extension 112 may include a protrusion 112 a that extends from both ends toward the center of the vertical extension 111 and protrudes.

  A substrate 140 to which the light emitting unit 120 and the sensor unit 130 are fixed is disposed in the inner space of the case 110. The substrate 140 serves to supply power for the operation of the light emitting unit 120 and the sensor unit 130, and allows the light emitting unit 120 and the sensor unit 130 to be fixed at a predetermined angle. Here, the substrate 140 is a substrate made of glass epoxy or FPC (Flexible Printed Circuit) that is generally used, and a current can flow, and power can be supplied to the light emitting unit 120 and the sensor unit 130 by the supplied power. Copper wires are arranged like this. The substrate 140 has a shape in which the upper and lower portions are bent toward the cooling fins 12 so that the light emitting unit 120 and the sensor unit 130 are inclined at a predetermined angle.

  The light emitting unit 120 is provided on the substrate 140 and plays a role of irradiating light toward the cooling fins 12. Although various light sources can be used as the light source of the light emitting unit 120, it is preferable to use an LED (Light Emitting Diode) light source that has the advantage of being bright and long in life while having low power consumption.

  An LED means a semiconductor element that emits light when a voltage is applied in the forward direction, and has an emission color ranging from an ultraviolet region to a visible light region and an infrared region depending on the material used. The LED has polarity, and emits light when a voltage is applied from the cathode (cathode) to the anode (anode), but no current flows even when the voltage is increased below a predetermined voltage. In addition, when a current flows at a predetermined voltage or higher, light having an intensity proportional to the amount of current is generated. An LED is preferable as the light emitting unit 120 of the present invention because it has a relatively simple structure and is inexpensive. As shown in FIG. 6, the light emitted from the light emitting unit 120 enters the cooling fin 12 at a predetermined angle (θ).

  The sensor unit 130 is provided on the substrate 140 and detects light emitted from the light emitting unit 120 and reflected by the cooling fins 12. The sensor unit 130 is provided at an angle corresponding to the light emitting unit 120. Here, the angle corresponding to the light emitting unit 120 means the same or similar angle as the angle at which the light emitting unit 120 is provided. This is for receiving the maximum amount of light irradiated from the light emitting unit 120 and partially scattered and reflected by the cooling fins 12. FIG. 6 shows a case where light emitted from the light emitting unit 120 enters the cooling fin 12 at an angle θ and then enters the sensor unit 130 at an angle θ ′. Here, θ and θ ′ are comparable values and have an angle difference in the range of 3 ° to 5 °.

  Since the light emitting unit 120 and the sensor unit 130 are provided at different positions instead of the same position, the light irradiated to the cooling fins 12 from the light emitting unit 120 is partially scattered and partially reflected by the cooling fins 12. In order to receive light by 130, the light emitting unit 120 and the sensor unit 130 must have a predetermined angle.

  FIG. 5 is a conceptual diagram of a defroster for an evaporator, where (a) shows a state in which a light emitting unit and a sensor unit are provided on a flat substrate, and (b) shows a predetermined angle between the light emitting unit and the sensor unit. And shows a state of being provided on the substrate.

  The light emitting unit 120 and the sensor unit 130 perform functions within an angle within a predetermined range. In the case where the light emitting unit 120 and the sensor unit 130 are arranged in parallel on a flat substrate as shown in FIG. 5A, there is no choice but to arrange them at a predetermined interval depending on the physical volume of the element. In this case, the light emitted from the center of the light emitting unit 120 is not detected at the center of the sensor unit 130, but the sensor unit 130 uses the cooling fin 12 for light emitted from the outer portion of the light emitting unit 120. Since the reflected light is detected, its efficiency is low.

  On the other hand, when the light emitting unit 120 and the sensor unit 130 are provided on the substrate 140 at a predetermined angle as shown in FIG. 5B, a virtual line extending from the center of the light emitting unit 120 and the sensor unit are provided. The virtual lines extending from the center of 130 can be arranged so as to intersect with each other, and they are in focus. The central part of the sensor unit 130 targets light emitted from the center of the light emitting unit 120. Since the light reflected by the cooling fin 12 is detected, the function can be executed with higher efficiency than when the light emitting unit 120 and the sensor unit 130 are arranged on a flat substrate as shown in FIG.

  The sensor unit 130 receives the light reflected by the cooling fins 12 and detects the frost and the amount of frost formed on the cooling fins 12. The sensor unit 130 is based on the principle that the LED light irradiated from the light emitting unit 120 and reflected and received by the cooling fin 12 made of aluminum and the intensity and color of the light change when frost forms on the cooling fin 12. It is possible to determine the frost that has formed on the cooling fins 12 and the amount of frost formed on the cooling fins 12.

  In the present invention, the sensor unit 130 may include an illuminance sensor, an RGB sensor, or a CMOS sensor (CMOS image sensor).

  The illuminance sensor refers to a sensor that detects the degree of light brightness, and means all sensors that can determine the light brightness including a CDS or a photodiode. Light brightness is measured in lux.

  For example, when the intensity of light emitted from the light emitting unit 120 is 200 lux, 150 lux is detected by the illuminance sensor when the frost is not frosted on the cooling fin 12, but the frost is frosted on the cooling fin 12. When the intensity of light detected by the illuminance sensor changes to 120 lux, the control unit can determine that frost has formed on the cooling fins 12 based on the received value. When the amount of frost formed on the cooling fins 12 is further increased, the difference in intensity of light received by the illuminance sensor is further increased, and the control unit determines the amount of frost formed on the basis of the difference, and the defrost heater The drive time of 14 and its intensity can be adjusted.

  The RGB sensor acquires a color image in the visible light region using red (Red, R), green (Green, G), and blue (Blue, B) pixels. The RGB sensor defines a specific color by the three primary colors of light, red, green, and blue, and is applied to the imaging system to convert the red, green, and blue colors into signals and send them to the signals. Based on this, it will be possible to reproduce the color image on the display. In recent years, RGB sensors are not only widely used to adjust the brightness and sharpness of screens used as parts for smartphones and digital cameras, but also for plating and dyeing by measuring the color in the plating and dyeing processes. It is also used to judge defects.

  Since the RGB sensor can detect the color of the direct light and transmit it as a specific analog signal, the white color is detected from the frost that has formed on the cooling fin 12, and frost forms on the cooling fin 12. It can be sufficiently applied to the use for detecting frost. In this case, the operation of the sensor unit 130 is realized using an RGB sensor instead of using expensive components such as a CCD camera and a DSLR camera that realize an image projected on the microlens as a digital image of various colors. be able to. The RGB sensor is configured in such a manner that a filter is provided on the front surface and integrated in a sensor holder, and then the sensor holder is detachably inserted into a cylindrical sensor case.

  For example, the cooling fins 12 made of aluminum have a black color when the frost is not frosted, but gradually become a white color when the frost is frosted, and are thus detected by the RGB sensor. The color changes. The RGB sensor detects the frost formed on the cooling fin 12 by detecting the change in the color, and when the change in the color increases, the control unit determines that the amount of frost formed is increased. Can do. For example, if the RGB sensor recognizes the value of black light as 10 and gradually becomes brighter and recognizes the value of white light as 0, the light emitted from the light emitting unit 120 and reflected by the cooling fin 12 is reflected. The measured value is changed by frost frosting and is output to the control unit, whereby the control unit can determine that frost has formed on the cooling fins 12.

  In the CMOS sensor, red (Red, R), green (Green, G1, G2), and blue (Blue, B) are arranged in a Bayer pattern. In particular, since “green” is a color in a medium wavelength region (about 450 nm) band that has the greatest influence on the human eye, when one pixel is assigned to “red” and “blue” to increase output. Two pixels are assigned to “green”. That is, “green” is divided into “G1” and “G2”, and a color image can be obtained by configuring pixels. The operation of the CMOS sensor is similar to the operation of the RGB sensor described above.

  Based on the value received by the sensor unit 130, the control unit plays a role of determining whether the cooling fins 12 are frosted or how much frost has been formed. Specifically, the control unit obtains a reference value that is input when frost is not frosted on the cooling fin 12 and a detection value of the sensor unit 130 that has changed due to frost frosting on the cooling fin 12. By performing the comparison calculation, it is determined whether the cooling fins 12 are frosted or how much frost has been formed.

  If the cooling fins 12 are frosted, this means that the frost has formed on the evaporator 10, so that the operation of the compressor 26 and the blower fan 25 is stopped and the defrosting heater 14 is operated to operate the defrosting heater 14. 14 transmits a signal for operation. When the value measured by the defroster 100 becomes equal to or higher than the reference value during the operation of the defrost heater 14, the operation of the defrost heater 14 is stopped, the compressor 26 and the blower fan 25 are operated, and the evaporator 10 is operated. The generated cold air is supplied to the freezer compartment 23 and the refrigerator compartment 22.

  FIG. 7 shows another embodiment of a defroster for an evaporator.

  The defrosting apparatus 200 of FIG. 7 is the same as the defrosting apparatus 100 of FIG. 6 in that it includes a case 210, a light emitting unit 220, a sensor unit 230, and a control unit (not shown), and these functions are described above. Street.

  Unlike the defrosting device 100 of FIG. 6, the defrosting device 200 is configured such that one end of the horizontal extension 212 of the case 210 does not protrude toward the center of the vertical extension 211 and extends toward the cooling fin 12. The entire surface is open toward the cooling fin 12. In this case, there is an advantage that various installation angles of the light emitting unit 220 and the sensor unit 230 can be set according to the installation environment.

  FIG. 8 shows still another embodiment of an evaporator defroster.

  8 includes a case 310, a light emitting unit 320, a sensor unit 330, and a control unit (not shown). In the defrosting apparatus 300, the vertical extension 311 is fixed to the support bracket 13 and is disposed between the support bracket 13 and the cooling fin 12. When the refrigerant flowing through the refrigerant pipe 11 absorbs ambient heat and the temperature falls, frost forms not only on the cooling fin 12 but also on the defroster 100, and the defroster 100 adheres to the cooling fin 12. There is a risk of malfunction when detecting frost. Therefore, the defrosting device 300 has a structure in which the transparent plate 313 is disposed on the front surface portion of the defrosting device 100 of FIG. 6 by providing the transparent plate 313 between the upper and lower protrusions 312a of the horizontal extension portion 312. Like that. In this case, the operations of the light emitting unit 320 and the sensor unit 330 are smoothed, and it is possible to prevent frost from forming on the light emitting unit 320 and the sensor unit 330 due to a decrease in the ambient temperature. The transparent plate 313 is made of various materials such as glass and synthetic resin.

  FIG. 9 shows still another embodiment of an evaporator defroster.

  The defrosting device 400 of FIG. 9 is similar to the defrosting device 300 of FIG. 8 in that it includes a case 410, a transparent plate 413, a light emitting unit 420, a sensor unit 430, and a control unit (not shown). The function is as described above.

  In addition to the defrosting apparatus 300 of FIG. 8, the defrosting apparatus 400 has a structure in which a heat wire 414 is further included in the case 410. The heat ray 414 generates heat by a power source supplied from the substrate 440 to which the light emitting unit 420 and the sensor unit 430 are fixed. The hot wire 414 plays a role of preventing a malfunction in detecting frost so that the temperature of the defrosting device 400 is maintained constant.

  FIG.10 and FIG.11 is a figure which shows the modification of the installation position of a defroster.

  The defroster 100 plays a role of detecting frost formed on the cooling fins 12, but is generally disposed between the support bracket 13 of the evaporator 10 and the cooling fins 12.

  However, when the defroster 100 cannot be provided between the support bracket 13 and the cooling fin 12 because the interval between the cooling fins 12 is too narrow, the defroster 100 is placed below the support bracket 13 as shown in FIG. The frost formed on the cooling fin 12 is detected by providing and extending the cooling fin 12 downward. In this case, the cooling fins 12 to be detected as frost formation are cooling fins 12 having a distance from the support bracket 13 that is larger than the width of the defroster 100.

  FIG. 11 shows a mode in which the installation example of FIG. 10 is applied to the support brackets 13 on both sides. In order to more accurately detect frost formed on the cooling fins 12, it is preferable to install the defrosting devices 100 at a plurality of locations of the support bracket 13 of the evaporator 10. FIG. 11 shows an example.

  The apparatus for detecting frost that has formed on the evaporator and the operation thereof have been described above. Below, the method to control the defrosting apparatus 100 is demonstrated.

  FIG. 12 is a diagram showing an operation process of the defroster of the evaporator. Referring to FIG. 12, in the defrosting apparatus 100, the light emitting unit 120 emits light toward the cooling fin 12 of the evaporator 10, and a part of the light incident on the surface of the cooling fin 12 is scattered. The part reflects and enters the sensor part 130. Then, the said control part compares the reference value set by experiment, and the value detected by the sensor part 130, and judges whether the frost has formed in the cooling fin 12 and the amount of frost formation. When it is determined that the cooling fins 12 are frosted, the control unit outputs a signal for stopping the driving of the compressor 26 and the blower fan 25 and a signal for driving the defrosting heater 14 respectively. Send.

  FIG. 13 is a flowchart showing an operation process of the defroster of the evaporator. The control method of the defrosting apparatus 100 includes a first stage, a second stage, and a third stage.

  In the first stage, when the compressor 26 is driven, the light emitting unit 120 provided in the case 110 emits light toward the cooling fin 12, and the sensor unit 130 detects the amount of light reflected by the cooling fin 12. It is the stage to do.

  Here, the light emitting unit 120 and the sensor unit 130 are provided to have a predetermined angle, the light emitting unit 120 emits light at a predetermined angle toward the cooling fin 12, and the sensor unit 130 is formed by the cooling fin 12. You may make it detect the quantity of the light to reflect. As the light source of the light emitting unit 120, an LED light source may be used as described above.

  In the second stage, when the amount of light detected by the sensor unit 130 is equal to or less than the first reference value, the defrost heater 14 is turned on to remove frost that has formed. In the second stage, when the value detected by the sensor unit 130 becomes lower than the second reference value and then becomes equal to or lower than the first reference value, a signal for turning on the defrost heater 14 is transmitted. The sensor unit 130 has a configuration as described above. The first reference value and the second reference value are arbitrarily set by the user.

  The third stage is a stage in which the defrosting heater 14 is turned off when the amount of light detected by the sensor unit 130 by driving the defrosting heater 14 is equal to or greater than the second reference value. In the third stage, when the value detected by the sensor unit 130 by driving the defrost heater 14 becomes higher than the first reference value and then becomes equal to or higher than the second reference value, a signal for turning off the defrost heater 14 Send.

  FIG. 14 is a graph showing the change in the value detected by the illuminance sensor and the operation of the defrost heater, compressor and blower fan over time according to the change.

  When frost is formed on the cooling fins 12 by driving the compressor, the illuminance of light irradiated and reflected from the light emitting unit 120 changes, but the sensor unit 130 detects the amount of frost that increases. The illuminance becomes lower and reaches the second reference value (time t1). At this time, the control unit transmits a signal (off signal) for stopping the driving of the compressor 26 and the blower fan 25.

  When the amount of frost frosted on the cooling fin 12 is further increased, the illuminance detected by the sensor unit 130 is further reduced, and when the first reference value is reached (time t2), the control unit turns the defrost heater 14 on. A signal to be driven (ON signal) is transmitted to drive the defrost heater 14.

  When the frost frosted on the cooling fin 12 is melted by driving the defrost heater 14 and the illuminance detected by the sensor unit 130 gradually increases and reaches the second reference value (time t3), the control unit A signal for turning off the frost heater 14 and a signal for turning on the compressor 26 and the blower fan 25 are transmitted. Here, the first reference value and the second reference value are values arbitrarily selected by the user, but the first reference value is smaller than the second reference value.

  The above-described evaporator defrosting device and control method thereof are not limited to the configuration and method of the above-described embodiment, and various modifications can be made by selectively combining all or part of each embodiment. can do.

DESCRIPTION OF SYMBOLS 10 Evaporator 11 Refrigerant tube 12 Cooling fin 13 Support bracket 14 Defrost heater 20 Refrigerator 21 Cabinet 22 Refrigeration room 23 Freezing room 24 Storage unit 25 Blower fan 26 Compressor 27 Cooling room 28 Machine room 29 Cold air duct 100 Defroster 110 Case 111 Vertical Extension Part 112 Horizontal Extension Part 112a Projection Part 120 Light Emitting Part 130 Sensor Part 140 Substrate

Claims (12)

Evaporation including cooling fins that are coupled to a refrigerant pipe through which refrigerant flows to exchange heat, a support bracket that supports the refrigerant pipe, and a defrost heater that supplies heat to remove frost that forms on the refrigerant pipe In the vessel
A light emitting unit for irradiating light toward the cooling fin provided on one side of the evaporator;
A sensor unit for detecting the amount of light reflected by the cooling fin;
A defroster for an evaporator, comprising: a controller that controls on / off of the defrost heater based on the detected value. The control unit turns on the defrost heater when the amount of light detected by the sensor unit is equal to or less than a first reference value, and the amount of light detected by the sensor unit is equal to or greater than a second reference value. If so, turn off the defrost heater,
The defroster for an evaporator according to claim 1, wherein the first reference value is smaller than the second reference value. The light emitting unit irradiates light at a predetermined angle toward the cooling fin,
The evaporator defrosting device according to claim 1, wherein the sensor unit is provided at an angle corresponding to the light emitting unit so as to detect light reflected by the cooling fin.   The defroster for an evaporator according to claim 1, wherein the sensor unit includes an illuminance sensor that detects the frost and the amount of frost formed on the cooling fin by detecting the brightness of light.   The defroster for an evaporator according to claim 1, wherein the sensor unit includes an RGB sensor that detects a frost formed on the cooling fin and an amount of frost formed by detecting a color of reflected light.   The defroster for an evaporator according to claim 1, further comprising a substrate for supplying power to the light emitting unit and the sensor unit and fixing the light emitting unit and the sensor unit at a predetermined angle.   The evaporator defrosting device according to claim 1, further comprising a case installed on the support bracket and disposed to face the cooling fin. The case is
A vertical extension for securing to the support bracket;
The evaporation according to claim 7, comprising: a horizontal extension that protrudes from both ends of the vertical extension toward the cooling fin so as to prevent liquid from flowing into the light emitting part and the sensor part. Defrosting device.   The defroster for an evaporator according to claim 8, wherein the horizontal extension is formed such that one end thereof is bent toward the center of the vertical extension.   2. The defroster for an evaporator according to claim 1, wherein the defroster is disposed between the support bracket and the cooling fin so as to face the cooling fin that is installed below the support bracket and extends downward. apparatus.   The defroster for an evaporator according to claim 1, wherein the defroster is installed at a plurality of locations below the support bracket. In a method of controlling a defrosting device configured to include a light emitting unit and a sensor unit and attached to an evaporator,
When the compressor is driven, the light emitting unit emits light toward the cooling fins of the evaporator, and the sensor unit detects the amount of light reflected by the cooling fins;
A second step of turning on the defrosting heater of the evaporator when the amount of light detected by the sensor unit is equal to or less than a first reference value;
And a third step of turning off the defrosting heater when the amount of light detected by the sensor unit by driving the defrosting heater exceeds a second reference value. .

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