KR102487029B1 - Defrost system for freezer - Google Patents

Abstract

This disclosure relates to a defrosting system for freezers and refrigerators. More particularly, the present disclosure relates to a system for removing frost that has formed on a cooler heat exchanger in a freezer during freezing or refrigerating, that is, performing defrosting. According to the present disclosure, the system is configured to comprise a condenser, a receiver, a filter dryer, a compressor, a liquid separator, a liquid injection valve, a liquid injection line, an evaporator, an expansion valve, and a four-way valve.

Description

Defrost system for freezer {DEFROST SYSTEM FOR FREEZER}

This disclosure relates to freezers for freezers and refrigerators. Specifically, the present disclosure relates to a system for removing frost that has formed on a cooler heat exchanger in a freezer during freezing or refrigerating, that is, performing defrosting.

"Refrigeration cycle" is a thermodynamic process in which heat is released at high temperature and high pressure by absorbing heat at low temperature and low pressure using a refrigerant, which is a substance that is sensitive to temperature and pressure. It is a reversible cycle that cools a specific object or space. As indicated, it has the same meaning known to a person of ordinary skill in the art to which this disclosure belongs (hereinafter referred to as "ordinary technician").

The refrigeration cycle consists of a compressor that compresses low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure gaseous refrigerant, a condenser that cools high-temperature and high-pressure gaseous refrigerant into high-temperature and high-pressure liquid refrigerant, and a high-temperature and high-pressure liquid refrigerant into low-temperature and low-pressure liquid refrigerant. It can be performed by a system composed of an expander that creates a low-temperature low-pressure liquid refrigerant by absorbing ambient heat and an evaporator that converts a low-temperature low-pressure gaseous refrigerant into a low-temperature low-pressure gas refrigerant.

Here, the low-temperature, low-pressure liquid refrigerant is changed to a low-temperature, low-pressure gaseous refrigerant, and the property of absorbing ambient heat is used in air conditioners (air conditioners), refrigerators, and freezers.

On the other hand, the property of dissipating heat to the surroundings as the high-temperature and high-pressure gaseous refrigerant is changed to a high-temperature and high-pressure liquid refrigerant is used as a heater, and in order to use the reversible characteristic in the refrigeration cycle system, the direction in which the refrigerant flows is changed in the middle If a 4-way valve is installed, it can also function as a heat pump that can perform both cooling and heating for a given object or space.

The air conditioner is a device to lower the indoor temperature when the outdoor air is hot. , At this time, condensate is generated by removing the moisture contained in the air while cooling the indoor (internal) air (dehumidification function).

At the beginning of operation of the refrigerator or freezer, the cooler, which is an indoor unit, cools the air in the refrigerator or freezer at room temperature and removes moisture. On the way, moisture in the air condenses and freezes in the evaporator, which is called condensation.

If frost occurs in the evaporator of a refrigerator or freezer, cooling performance deteriorates, and if the frost becomes severe, frost accumulates inside the evaporator, making it difficult to cool. Therefore, for a refrigerator or freezer, it is necessary to periodically remove the frost that has formed on its evaporator, which is called defrosting.

Referring to FIGS. 1A to 1C , an example in which components constituting a refrigerator are generally installed is shown.

Referring to FIG. 1A, a freezer 11 and a refrigerator 12, which is an outdoor unit equipped with a compressor and a condenser outside the freezer 11, are exemplified. Typically, the freezer 12 includes a fan for cooling the condenser and A controller for controlling power supply and operation of the fan is included.

Referring to FIG. 1B, a cooler 13 installed in the freezer 11 is illustrated, which is an indoor unit including an evaporator for cooling the inside of the freezer 11, and a low-temperature, low-pressure liquid refrigerant of high temperature and high pressure is supplied to the inlet of the evaporator. The cooler 13 may include an expander (also referred to as an expansion valve) that converts the liquid refrigerant into a liquid refrigerant, a fan that assists the evaporator to absorb heat, and a device for defrosting (such as an electric heater). A view of the inside of the open cooler 13 from the left side of the cooler 13 is the same as, for example, FIG. 1C.

As described above, in order to maintain the performance of the freezer, it is necessary to defrost the freezer, and defrosting methods include heater defrost, hot gas defrost, water spray defrost, thermal storage defrost, and reverse cycle defrost.

First, heater defrost is a type inserted into an existing evaporator, and is the most widely used because of its simple structure, low price, and simple control because it only needs to control power supply and shutdown. However, there is a disadvantage in that it takes a long time to heat the whole by inserting a heater into a part of the evaporator, and the long-term defrosting increases the temperature in the furnace, resulting in deterioration of storage quality and long cooling operation time after defrosting, resulting in high power consumption.

Next, hot gas defrosting uses a high-temperature and high-pressure gaseous refrigerant and has a fast defrosting speed. Since the defrosting time is short and the temperature change in the furnace is small, storage quality is good and power consumption is low. On the other hand, since a separate hot gas line is required and a separate device for reheating the liquid refrigerant condensed in the evaporator after defrosting into a gaseous refrigerant is also required, the structure is complicated and it is difficult to configure a complete cycle (some liquid return, some possibility of overheating).

Water spray defrost has the advantage of fast defrosting speed by directly spraying water (defrost water) at room temperature. Separate power consumption is low and defrosting time is short, so there is little change in furnace temperature and good storage quality. It is necessary to prevent a problem in which a large amount of water vapor is generated and scattered around the evaporator and outside thereof, and additional facilities such as a supply device and a drainage device for defrosting water are separately required.

Thermal storage defrost uses the hot water stored in the condenser before heat dissipation during refrigeration operation, so the defrost is relatively fast, resulting in little change in the temperature inside the refrigerator and low power consumption. Since the line must be built, the structure is complicated, and the size of the cooler and freezer becomes considerably larger.

A reverse cycle defrosting method may also be used for defrosting a heat pump for air conditioning. A heat pump is a device that can perform both cooling and heating for a space by attaching a four-way valve that reverses the flow of refrigerant to an air conditioner and reversing the roles of a condenser and an evaporator. For example, in summer, when the refrigerant removes indoor heat from the evaporator in the indoor unit, the compressor changes the refrigerant to high-temperature and high-pressure and sends it to the condenser in the outdoor unit, where it can function as an air conditioner by discarding heat to the outside. . Conversely, in winter, the flow of refrigerant changes in all directions, the refrigerant absorbs heat from the evaporator in the outdoor unit, and the compressor converts it to a high temperature and high pressure. It can function as a type of heater.

In general, frost does not occur in the evaporator of the air conditioner, but in the case of the heater, since the evaporator is outside and frost occurs as the outdoor temperature drops below 5 degrees Celsius, defrosting is required. Defrosting of the heat pump temporarily switches to cooling operation during heating operation so that the outdoor evaporator acts as a condenser and the high-temperature and high-pressure refrigerant removes the frost. refers to

Reverse cycle defrosting also has a short defrosting time and low temperature change in the freezer, so the storage quality is excellent and power consumption is low. do. More specifically, in the reverse cycle defrost, a hot gas pipe for defrosting the drain plate is connected in parallel with the evaporator, a fixed capillary for defrosting operation is used to prevent the low pressure of the refrigerant, and a liquid to prevent the inhalation of the low temperature and low pressure refrigerant. A gas heat exchanger is used.

Among various defrosting methods, heater defrosting is the most widely used because of its simple structure and control, and other methods are good in terms of effects, but have problems such as a complicated structure and leading to cost increase.

Reverse cycle defrosting is simpler and less costly than other methods except for heater defrosting, but since the method used in heat pumps is applied as it is, it solves problems such as low pressure management, drainage of defrost water, and liquid refrigerant return due to rapid operation switching. There are several hurdles to be faced with.

For example, as an example of the prior art related to defrosting of a conventional refrigerator, first, referring to Korean Registered Patent No. 10-1715863, which employs a drain plate defrosting method, a heat exchanger for defrosting a drain plate at the bottom of the heat exchanger In this case, there is no problem in that the refrigerant flows only during defrosting by connecting in parallel with the upper evaporator. The temperature of the heat exchanger for defrosting the lower drain plate is lowered by the cold defrost water and the mechanical check valve is closed, preventing complete drainage. As an ice tunnel is formed, there is a problem in that defrosting may not be possible. In order to solve this problem, if an electronic valve is used instead of a mechanical check valve, the valve is closed, but the upper heat exchanger is defrosted first, and the lower drain part is completely drained and the defrost is not completed before removing residual snow. In addition, even after defrosting is completed, water droplets remain in the upper heat exchanger with less drainage, and during freezing operation, they are immediately frozen and degrade refrigerating performance.

In order to solve this problem, the present disclosure proposes a method of connecting a heat exchanger for defrosting a drain plate in series with an upper evaporator and defrosting the lower part of the heat exchanger first and then defrosting the upper part during the defrosting operation. The lower part is defrosted first before the defrost water and remaining snow fall, and the upper part is defrosted after the lower part is defrosted and drained, so that all the defrost water inside the drain plate is drained and all the water droplets inside the heat exchanger fin at the top can be removed. there is.

In addition, in the prior art document, a defrost-only fixed ball valve is added as an expansion valve for defrost operation separately from an expansion valve for refrigeration. However, fixed ball valves work properly only under certain conditions and cause damage to the compressor due to overheating or overcooling when the ambient temperature is slightly higher or lower. . In the same prior art document, it is described that the conventional thermal expansion valve (TXV) does not work properly because the evaporation temperature is low. However, when the fan is started during defrosting operation, the evaporation temperature is sufficiently high, so there is no problem with the use of the thermal expansion valve. According to the literature, the TXV for refrigeration, two by-pass check valves, and a fixed ball valve are required, so the structure is very complicated.

In order to solve this problem, the present disclosure overcomes the problem of low evaporation temperature during defrosting by operating a freezer fan, and is a two-way external balance type temperature reduction that is different from the conventional temperature control expansion valve (one-way, internal balance type) for freezing and defrosting for both freezing and defrosting purposes. Since the expansion valve is installed in an outdoor freezer, its structure is simple and its location is near the compressor, so overheating or overcooling of the compressor can be solved.

As such, the present disclosure intends to propose a defrosting system capable of overcoming the difficulties in reverse cycle defrosting while adopting a reverse cycle defrosting method capable of solving the problems of various defrosting methods including the above-mentioned prior art literature.

KR 10-1715863 B1

Accordingly, an object of the present disclosure is to provide a defrosting system that enables economical operation by solving the above-described problems of the conventional defrosting system.

The characteristic configuration of the present invention for achieving the object of the present invention as described above and realizing the characteristic effects of the present invention described later is as follows.

According to one aspect of the present disclosure, a defrost system for a refrigerator is provided, the defrost system is a condenser 101, by condensing the gaseous refrigerant flowing into the condenser 101 during a freezing operation of the refrigerator a condenser (101) discharging liquefied refrigerant from the gaseous refrigerant; A compressor 105 including a first port and a second port, compressing the gaseous refrigerant flowing into the compressor 105 during the refrigeration operation to discharge the gaseous refrigerant whose temperature and pressure are higher than that of the incoming gaseous refrigerant compressor 105; As a liquid injection valve 107 connected to the condenser 101, when the temperature of the compressor 105 is higher than a predetermined threshold temperature during the freezing operation, a liquid injection valve (107) for flowing at least a portion of the liquid refrigerant discharged from the condenser (101) toward the first port of the compressor (105); As a liquid injection line 108, which is a first capillary connecting the liquid injection valve 107 and the first port of the compressor 105, flowing from the liquid injection valve 107 toward the compressor 105 a liquid injection line 108 for reducing the temperature and pressure of the liquid refrigerant; an evaporator 109 which evaporates the liquid refrigerant flowing into the evaporator 109 during the freezing operation and discharges the vaporized gaseous refrigerant from the liquid refrigerant; a first line branching between the condenser 101 and the liquid injection valve 107; An expansion valve 110 connected between the first line and the evaporator 109 to control the direction of flow, enabling a first flow from the condenser 101 toward the evaporator 109 during the freezing operation. Expansion valve 110 to do; and four ports, wherein the four ports are connected to the condenser (101), to the second port of the compressor (105), to the evaporator (109), and to the first port of the compressor (105). and a 4-way valve 112 each connected to a joining point 111 formed between the liquid injection line 108 and directed toward the condenser 101 from the compressor 105 during the refrigeration operation. It includes a quadrilateral 112 enabling only a second flow and a third flow from the evaporator 109 toward the confluence point, and the evaporator 109 includes coils formed to alternate in a zigzag shape and surrounding the coils. an integrated heat exchanger including a plurality of fins spaced apart from each other at predetermined intervals so as to; hot gas pipes alternately formed in a zigzag shape and connected in series to the heat exchanger; a bypass connected in series with the heat exchanger and connected in parallel with the hot gas pipe; and a control valve installed in the bypass to control the flow of the bypass by opening and closing.

Preferably, the defrosting system is a receiver 102 connected to the condenser 101 between a point at which the first line diverges and the condenser 101, and the receiver 102 is connected to the condenser 101 during the freezing operation. ) Further comprising a receiver 102 for collecting the liquefied refrigerant flowing into the refrigerant and discharging the liquid refrigerant from among the liquefied refrigerant.

More preferably, the defrosting system is a filter dryer 103 connected to the receiver 102 between the point at which the first line diverges and the receiver 102, and the filter during the freezing operation A filter dryer 103 filtering moisture contained in the liquid refrigerant flowing into the dryer 103 is further included.

Advantageously, the defrosting system comprises a liquid separator 106 connected to the first port of the compressor 105 between the first port of the compressor 105 and the joining point 111, wherein the refrigerating A liquid separator 106 for flowing only gaseous refrigerant among the refrigerants flowing toward the compressor 105 to the compressor 105 by collecting and evaporating liquid from the refrigerant flowing toward the compressor 105 during operation. include

Preferably, during a defrosting operation of the refrigerator, the expansion valve enables a fourth flow from the filter dryer to the evaporator, and the four sides enable a fifth flow from the compressor to the evaporator and a flow from the condenser. Only the sixth flow toward the confluence point is enabled, and flow directions of the fluid flowing in and out of the condenser, the receiver, and the filter dryer are opposite to those of the freezing operation.

More preferably, the evaporator includes an integral heat exchanger including a coil formed to alternate in a zigzag shape and a plurality of fins spaced apart at predetermined intervals to surround the coil; hot gas pipes alternately formed in a zigzag shape and connected in series to the heat exchanger; a bypass connected in series with the heat exchanger and connected in parallel with the hot gas pipe; and a control valve installed in the bypass to control the flow of the bypass by opening and closing.

Even more preferably, during the freezing operation, the control valve is opened so that the refrigerant flowing into the evaporator is sequentially discharged from the evaporator via the integrated heat exchanger and the bypass, and during the defrosting operation, the freezing operation The control valve is closed so that the refrigerant entering the evaporator in a direction different from the time of day is sequentially discharged from the evaporator via the hot gas pipe and the integrated heat exchanger.

In one embodiment, the evaporator is for refrigeration, and the distance between the fins is 5 mm to 7 mm.

In another embodiment, the evaporator is for freezing, and the interval between the fins is 9 mm to 12 mm.

Advantageously, the expansion valve is an externally balanced bidirectional thermal expansion valve (TXV), and the defrosting system comprises: a temperature sensing means installed between the liquid separator and the compressor to measure the temperature of the refrigerant upstream of the compressor; a second capillary tube connecting the temperature sensing means and the expansion valve; and a third capillary configured to connect between the liquid separator and the compressor and the expansion valve to measure the pressure of the refrigerant upstream of the compressor.

Preferably, the defrosting system comprises: a second line connecting between the four sides and the joining point and between the four sides and the compressor; and a pressure equalization valve installed on the second line, which is opened when the compressor is stopped to equalize the pressure upstream of the compressor and the pressure downstream of the compressor, but is kept closed when the compressor is not stopped. more includes

Advantageously, the defrost system further comprises a high and low pressure switch configured to stop the compressor when at least one of the pressure upstream of the compressor and the pressure downstream of the compressor is lower than a preset lower limit value or higher than a preset upper limit value.

In one embodiment, the defrosting system further includes a sight glass downstream of the filter drier.

According to an embodiment of the defrosting system proposed in the present disclosure, a relatively wide interval between fins is secured in preparation for use for freezing, so that frosting is relatively delayed.

According to an embodiment of the system of the present disclosure, since the evaporator can be placed outdoors and the fan can be operated during defrosting, the evaporation temperature increases, resulting in a very fast defrosting speed.

According to one embodiment of the system of the present disclosure, since the lower part of the evaporator can be defrosted first, there is an effect of resolving a phenomenon in which the flow passage below the inside of the evaporator is clogged due to residual snow.

The present inventors were able to confirm that the desired defrosting performance and economical efficiency in power consumption were achieved by actually verifying the solution of the present disclosure.

For the understanding of the present invention, embodiments will be described with reference to the accompanying drawings in order to show a defrosting system for a refrigerator and a control method thereof shown in the present disclosure, which are only non-limiting examples, and for those skilled in the art Of course, other drawings may be obtained on the basis of these drawings without additional effort leading to further inventions.
1A to 1C are diagrams showing examples in which general components constituting a conventional refrigerator are installed.
2 is a diagram illustrating the structure of a conventional general evaporator.
3 is an exemplary view showing the inside of a conventional evaporator in detail.
4 is a view showing the configuration of a defrosting system for a refrigerator according to the present disclosure illustratively together with a direction of fluid flow during a refrigerating operation.
5 is a view showing the configuration of a defrosting system for a refrigerator according to the present disclosure illustratively along with a direction of fluid flow during a defrosting operation.
Figure 6a is a diagram showing the configuration of the inside of the evaporator according to the present disclosure along with the direction of fluid flow during a freezing operation, and Figure 6b is a diagram showing the configuration inside the evaporator according to the present disclosure along with the direction of fluid flow during a defrosting operation It is a drawing shown by way of example with directions.

Unless defined otherwise, all terms used in this disclosure, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this specification, it should not be interpreted in an ideal or excessively formal meaning. don't

The detailed description below regarding the configuration principle of the defrosting system for a refrigerator and a control method thereof according to the present disclosure may be implemented in order to clarify the objects, technical solutions, and advantages of the present disclosure. Reference is made to the accompanying drawings, which illustrate specific embodiments of the present invention by way of example. In the description with reference to the accompanying drawings, the same reference numerals are given to the same components regardless of reference numerals, and overlapping descriptions thereof will be omitted. It will be understood that the structure of the system according to the present disclosure does not have length ratios as shown in the drawings, and the dimensions of each part in the drawings are shown only for purposes of explanation and do not limit the scope of the present invention. For example, the dimensions of some of the elements shown in the drawings are to aid understanding of various embodiments. In addition, the description and drawings are not meant to be written in the order in which they are written. Those skilled in the art will appreciate that acts and/or steps described or illustrated in a particular order may require no particular limitation to such order.

Accordingly, specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only, and may be modified and implemented in various forms.

And although terms such as first or second may be used to describe various components, these terms should be interpreted only for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element.

It should be understood that when an element is referred to as being “connected” to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. In addition, it should be understood that when an element is referred to as being 'on' another element, it may be 'directly on' the other element, but another element may exist in the middle.

Singular expressions include plural expressions and vice versa, unless the context clearly dictates otherwise.

In the present disclosure, the expression disposed "on", the expression disposed "on", and the expression disposed "between", unless otherwise specified, are arranged to be in direct contact with each other or interposed therebetween. It means that it was so arranged indirectly through other components. Moreover, "on ~" and "on ~" merely represent relative positions of components, because they may be seen differently depending on an observer's point of view. In addition, being formed "on (on)" has a broad meaning, and the fact that a component is formed on another component does not always mean a direct physical contact of a component to the other component.

In the present disclosure, "freezer" is a term referring to freezers, refrigerators, etc. used in actual fields, and it is well known to those skilled in the art that freezers and refrigerators have different specific applications, but their operating principles are substantially the same. . Therefore, since the "freezer" described in the description and claims of the present disclosure is described as a representative for convenience, it will be understood that it includes not only a freezer but also a refrigerator. Likewise, it will be understood that "freezer" includes "refrigerator".

In the present disclosure, "high temperature" and "low temperature" do not refer to temperatures above or below a certain threshold, but should be understood as relative concepts, and "high temperature" refers to normal temperature, room temperature, or "low temperature" It will be understood that "low temperature" is a term used to mean a temperature higher than the temperature referred to as ", and conversely, "low temperature" is a term used to mean a temperature lower than normal air temperature, room temperature, or the temperature referred to as "high temperature." .

In this disclosure, "upstream" expressed in relation to a path along which a pressure gradient is generated is a term referring to a location of relatively high pressure, and "downstream" refers to a location of relatively low pressure. As a denoting term, it will be understood that the fluid flows from upstream to downstream in its path.

Moreover, the present invention covers all possible combinations of the embodiments presented herein. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be implemented in one embodiment in another embodiment without departing from the spirit and scope of the invention. That is, the embodiments of the present invention are described with reference to specific drawings of ideal embodiments of the present invention, but should not be considered as being limited to a specific shape as shown, and various modifications may be included. The shapes shown in the drawings are conceptually shown, and are not intended to limit the scope of the present invention by limiting the precise shape of a structure or region. For example, a region shown as a rectangle, square, etc. in the drawings may be variously deformed in shape, such as being tapered, curved, or rounded.

It should be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. Accordingly, the detailed description set forth below is not to be taken in a limiting sense, and the scope of the present invention, if properly described, is limited only by the appended claims, along with all equivalents as claimed by those claims.

In addition, in describing the present invention, if it is determined that the detailed description of a related known configuration or function is related to materials, processes, etc. well known to those skilled in the art and may obscure the gist of the present invention, it is excessively concerned. Detailed descriptions are omitted.

2 is a diagram illustrating the structure of a conventional general evaporator.

The outdoor unit of the heat pump and the cooler of the refrigerator act as an evaporator in the refrigeration cycle, but the outdoor unit of the heat pump usually absorbs heat from the outdoor air in winter, and the cooler of the refrigerator cools the indoor air of the freezer. There are differences that play a role.

Referring to FIG. 2, the evaporator 20 includes a pipe 21 (eg, copper pipe) for circulating the refrigerant, and a fin 22 (eg, aluminum fin) for promoting heat transfer between the refrigerant and air, A low-temperature, low-pressure liquid refrigerant 23 (not shown) flowing in the pipe enables heat exchange through fins 22 and air 25 circulated by a fan 24.

Since the purpose of the evaporator (outdoor unit) of the heat pump is to absorb as much heat as possible from the outdoor air and dissipate it indoors, the fins should be arranged at relatively tight intervals (for example, up to 1 mm at least) to increase the heat exchange capacity. can During the heating operation of the heat pump, since the outdoor air in the middle of winter is dry, frosting does not occur well, so defrosting is unnecessary. .

In contrast, since the purpose of the evaporator (cooler) of the refrigerator in the present disclosure is to lower the temperature in the freezer to -20 degrees Celsius, the heat exchange capacity is also important, but it is more important to prevent a decrease in heat exchange capacity due to freezing during cooling Therefore, the fins can be arranged at relatively wide intervals (eg, 5 mm to 7 mm for refrigeration and 9 to 12 mm for freezing). In the case of a freezer, frosting can proceed from moisture evaporated from stored items and moisture in the air introduced when items are moved in and out, so if there is little entry and exit, defrosting is unnecessary even within 24 hours, and even if the entry and exit is frequent, the defrost phase can be entered. It takes at least 3-4 hours to complete.

Figure 3 is an exemplary diagram showing the inside of a conventional evaporator in detail, Figure 3 shows the inside viewed from the side of the evaporator.

Referring to FIG. 3, heater defrosting, which accounts for the majority of the freezer defrosting method, stops the operation of the freezer during defrosting and applies power to the electric heater 31 inserted between the coils inside the evaporator 30 to cool the inside of the evaporator. It is a way to melt conceived frost.

It takes a relatively long time for the temperature of the entire heat exchanger to reach the zero level by the heating of the heater 31 inserted in a part of the evaporator at -30 degrees Celsius or less, and 20 to 30 minutes to complete defrosting depending on the degree of frost It may take approx.

If the temperature of the freezer rises during defrosting and the frozen stored goods are thawed, the freezing is repeated after the defrosting is completed, so the storage quality may deteriorate.

Heater defrost has a disadvantage in that the defrosting time is relatively long and the time required to reach the freezing temperature is long even after completion of the defrosting, resulting in high power consumption. From the point of view of entering the defrost, the defrost phase is entered using a timer regardless of frosting (usually 4 times a day), so the quality of stored products is reduced due to repeated defrosting, and power is wasted due to unnecessary repetition of defrosting and long defrosting time. There is a disadvantage that occurs.

Now, the defrosting system will be described in detail in the present disclosure with reference to FIGS. 4 to 6B.

4 is a view showing the configuration of a defrosting system 100 for a refrigerator according to the present disclosure exemplarily together with a direction of fluid flow during a freezing operation of the refrigerator.

Referring to FIG. 4 , during the freezing operation, the condenser 101 condenses the gaseous refrigerant flowing into the condenser 101 and discharges the liquefied refrigerant from the gaseous refrigerant.

The receiver 102 connected to the condenser 101 is configured to collect the liquefied refrigerant flowing into the receiver 102 and discharge only the liquid refrigerant from among the liquefied refrigerant.

Then, the filter dryer 103 connected to the receiver 102 filters out moisture contained in the liquid refrigerant flowing out of the receiver 102 and flowing into the filter dryer 103.

The compressor 105 compresses the gaseous refrigerant flowing into the compressor 105 during the freezing operation and discharges the gaseous refrigerant whose temperature and pressure are higher than that of the incoming gaseous refrigerant.

The liquid separator 106 connected to the compressor 105 collects and evaporates liquid from the refrigerant flowing toward the compressor 105 so that only gaseous refrigerant among the refrigerant flowing toward the compressor 105 flows to the compressor 105. It consists of

The liquid injection valve 107 connected to the filter drier 103 controls at least a portion of the liquid refrigerant discharged from the filter drier 103 when the compressor 105 is higher than a predetermined threshold temperature during the freezing operation, that is, when overheated. to flow toward the liquid separator 106. The liquid injection valve 107 may be configured as a solenoid valve (SOL V/V), but is not limited thereto.

The liquid injection line 108, which is a first capillary connecting the liquid injection valve 107 and the liquid separator 106, controls the temperature and pressure of the liquid refrigerant flowing from the liquid injection valve 107 toward the liquid separator 106. reduce In other words, the high-temperature and high-pressure liquid refrigerant is changed into a low-temperature and low-pressure liquid refrigerant by the liquid injection line 108 .

The evaporator 109 is configured to evaporate the liquid refrigerant flowing into the evaporator 109 during the freezing operation and discharge the vaporized gaseous refrigerant from the liquid refrigerant.

The expansion valve 110 is connected between the first line branching between the filter dryer 103 and the liquid injection valve 107 and the evaporator 109, and is configured to adjust the direction of flow. During the freezing operation, the expansion valve 110 enables a first flow from the filter dryer 103 toward the evaporator 109 .

The four-way valve 112 has four ports, the first port of which is connected to the condenser 101, the second port is connected to the compressor 105, and the third port is connected to the evaporator 109, and the fourth port is connected to the junction point 111 formed between the liquid separator 106 and the liquid injection line 108. During the freezing operation, the four sides 112 enable a second flow from the compressor 105 toward the condenser 101, and also enable a third flow from the evaporator 109 toward the confluence point 111.

FIG. 5 is a diagram illustratively showing the configuration of the defrosting system 100 for a refrigerator according to the present disclosure along with a direction of fluid flow during a defrosting operation.

Referring to FIG. 5 , during the defrosting operation, the expansion valve 110 enables a fourth flow from the filter dryer 103 toward the evaporator 109 .

During the defrosting operation, the four sides 112 enable a fifth flow from the compressor 105 toward the evaporator 109 and enable a sixth flow from the condenser 101 toward the joining point 111 .

During the defrosting operation, the flow direction of the fluid flowing in and out of the condenser 101, the receiver 102, and the filter dryer 103 is opposite to the flow direction of the fluid during the freezing operation. That is, it can be said that the defrosting operation belongs to reverse cycle defrosting.

Preferably, the expansion valve 110 in the defrosting system of the present disclosure may be an externally balanced bidirectional thermal expansion valve (TXV).

A temperature sensing means (113) for measuring the temperature of the refrigerant upstream of the compressor (105) is installed between the liquid separator (106) and the compressor (105) so that the externally balanced bidirectional temperature sensing expansion valve (110) can function. A capillary tube 114 may be configured to connect between the temperature sensing means 113 and the externally equalized bi-directional temperature sensing expansion valve 110 . The temperature sensing unit 113 may be a temperature sensing rod, but is not limited thereto.

In addition, the third capillary tube 115 connects the expansion valve 110 between the liquid separator 106 and the compressor 105 so that the external equalization type bi-directional thermostatic expansion valve 110 can measure the pressure of the refrigerant upstream of the compressor 105. They can be configured to connect to each other.

Figure 6a is a conceptual side cross-sectional view showing the internal configuration of the evaporator according to the present disclosure along with the direction of fluid flow during a freezing operation, and FIG. Conceptual cross-sectional side view, illustratively shown along with the direction of fluid flow.

It is well known that each of the evaporator 109 and the condenser 101 may further include a fan to assist heat exchange. Conventionally, an indoor heat exchanger functioning as an evaporator during defrosting of a heat pump cannot operate a fan of the evaporator because it is located indoors. This is because when the temperature of the indoor heat exchanger is low during defrosting and the fan is operated, there is a problem in that cold air is blown into the room. In contrast, in the defrosting system 100 according to the present disclosure, during reverse cycle defrosting of the refrigerator in which the roles of the condenser and the evaporator are reversed, the condenser 101 serving as the evaporator is located outdoors, so by operating the fan In addition to the above problem, the evaporation temperature increases when the fan is operated, so that the problem of low-temperature and low-pressure liquid refrigerant being sucked into the compressor in the prior art can be solved, and the defrosting time is shortened.

However, when the fan of the condenser 101 is operated in summer, the high temperature and high pressure may be a burden on the compressor 105, but the pressure and temperature are liquid injection by the liquid injection valve 107 and the liquid injection line 108. Reliability of the system 100 can be ensured because it can lower .

In addition, in order to protect the compressor 105 by lowering the pressure and temperature, the defrosting system 100 is configured such that at least one of the pressure upstream of the compressor 105 and the pressure downstream of the compressor 105 is lower than a preset lower limit or It may further include a high and low pressure switch 117 configured to stop the compressor 105 when it is higher than a preset upper limit value.

In short, during reverse cycle defrosting of the defrosting system 100, since the fan of the outdoor condenser 109 can be operated, the defrosting time can be shortened by increasing the suction and discharge pressures of the compressor 105.

6A and 6B, the evaporator 109 includes a coil 212 formed to alternate in a zigzag shape and a plurality of fins 214 (not shown) installed at predetermined intervals to surround the coil. Including an integrated heat exchanger 210 that includes.

The integrated heat exchanger 210 may be configured in such a way that a lower heat exchanger for drain plate defrosting is disposed below the upper heat exchanger.

In the evaporator 109 , the hot gas pipes 220 are formed alternately in a zigzag shape and are configured to be connected in series with the heat exchanger 210 .

The bypass 230 is connected in series with the heat exchanger 210 and connected in parallel with the hot gas pipe 220, as illustrated in FIGS. 6A and 6B. An openable and closable control valve 232 is installed in the bypass 230 to control the flow of the bypass 230 . The control valve 232 may be a check valve, but is not limited thereto.

Referring to FIG. 6A, during the freezing operation, the refrigerant flowing into the evaporator 109 (202) is sequentially passed through the integrated heat exchanger 210 and the bypass 230 and flows out (204) from the evaporator 109 through a control valve. (232) is open.

Meanwhile, referring to FIG. 6B, during the defrosting operation, the direction in which the refrigerant flows into the evaporator 109 (202') is different from that during the freezing operation. The control valve 232 is closed so that the incoming refrigerant first passes through the hot gas pipe 220 and exits 204' from the evaporator 109 via the integral heat exchanger 210.

If the evaporator 109 is for refrigeration, that is, if the freezer of the defrosting system 100 is for refrigeration, the spacing between the fins 214 may be 5 mm to 7 mm. Alternatively, if the evaporator 109 is for freezing, that is, if the freezer of the defrosting system 100 is for freezing, the spacing between the fins 214 may be 9 mm to 12 mm.

Referring back to FIG. 5 , the defrosting system 100 may further include a second line connecting between the four sides 112 and the joining point 111 and between the four sides 112 and the compressor 105, A pressure equalization valve 116 may be installed on the second line. When the compressor 105 stops, the equalization valve 116 opens to balance the pressure upstream of the compressor 105 and the pressure downstream of the compressor 105. make them equal to each other On the other hand, it remains closed when the compressor 105 is not stopped. The equalization valve 116 may be configured as a solenoid valve, but is not limited thereto.

Defrosting entry, in which the defrosting system 100 switches from freezing operation to defrosting operation, and defrosting termination, switching from defrosting operation to freezing operation, are mainly performed by switching the flow direction of the four sides 112. Conventionally, for such switching, It is common to stop the compressor 105 and wait for a pressure difference between the high pressure part and the low pressure part to be resolved for a waiting time of at least 40 seconds to about 1 minute, and then operate the four-way valve 112 again. This is because an impact sound may be generated due to a pressure difference when the four-way valve 112 is operated immediately without such waiting time.

Therefore, the second line and the equalization valve 116 resolve the pressure difference between both ends of the second line immediately after the compressor 105 is stopped within a predetermined waiting time, for example, 20 seconds, so that the impact sound can be removed. Bar, the total time required for defrosting is shortened, and the reliability of the defrosting system 100 is improved by smoothly proceeding with entering and ending defrosting.

In addition, the defrosting system 100 may further include a sight glass 104 downstream of the filter dryer 103 .

In short, according to the system of the present disclosure described above, the progress of frosting is slowed down and the defrosting speed is increased, so that the performance of defrosting is improved and the economical efficiency in power consumption is improved. there is.

Although the present invention has been described above with only a few selected embodiments, those skilled in the art can easily understand the concept on which this disclosure is based, and the concept as a design basis for modified devices for performing some objects of the present invention. will be able to easily use

The foregoing examples are merely illustrative of several possible embodiments of various aspects of the present disclosure, and equivalent modifications may be made by others skilled in the art after reading and understanding this specification and the accompanying drawings. Changes and/or modifications will occur. In addition, even though a particular feature of this disclosure may have been described and/or illustrated with respect to only one of several embodiments, such a feature may be preferred in any given application or in one or more other embodiments of other embodiments that may be advantageous in a particular application. Features can be combined. Also, to the extent that the words "comprising," "includes," "including," "has," "including," or variations thereof are used in the description and/or claims, such terms It is intended to be inclusive in a manner similar to the term "comprising".

100: defrost system
101: condenser
102: receiver
103: filter dryer
104: sight glass
105: compressor
106: liquid separator
107: liquid injection valve
108: liquid injection line
109: evaporator
110: expansion valve
111: confluence
112: quadrilateral
113: temperature reduction means
114: second capillary
115: third capillary
116: equalization valve
117: high and low pressure switch
202, 202': inlet
204, 204': outlet
210: heat exchanger
212 Coil
214: fins
220: hot gas pipe
230: detour
232: regulating valve

Claims (9)

In the defrosting system for a refrigerator,
A condenser 101 which condenses the gaseous refrigerant flowing into the condenser 101 during the freezing operation of the refrigerator and discharges the liquefied refrigerant from the gaseous refrigerant;
A compressor 105 including a first port and a second port, compressing the gaseous refrigerant flowing into the compressor 105 during the refrigeration operation to discharge the gaseous refrigerant whose temperature and pressure are higher than that of the incoming gaseous refrigerant compressor 105;
As a liquid injection valve 107 connected to the condenser 101, when the temperature of the compressor 105 is higher than a predetermined threshold temperature during the freezing operation, a liquid injection valve (107) for flowing at least a portion of the liquid refrigerant discharged from the condenser (101) toward the first port of the compressor (105);
As a liquid injection line 108, which is a first capillary connecting the liquid injection valve 107 and the first port of the compressor 105, flowing from the liquid injection valve 107 toward the compressor 105 a liquid injection line 108 for reducing the temperature and pressure of the liquid refrigerant;
an evaporator 109 which evaporates the liquid refrigerant flowing into the evaporator 109 during the freezing operation and discharges the vaporized gaseous refrigerant from the liquid refrigerant;
a first line branching between the condenser 101 and the liquid injection valve 107; An expansion valve 110 connected between the first line and the evaporator 109 to control the direction of flow, enabling a first flow from the condenser 101 toward the evaporator 109 during the freezing operation. Expansion valve 110 to do; and
including four ports, wherein the four ports connect to the condenser (101), to the second port of the compressor (105), to the evaporator (109), and to the first port of the compressor (105). 4-way valves 112 each connected to the junction 111 formed between the liquid injection lines 108, and directing the compressor 105 toward the condenser 101 during the freezing operation. Four sides 112 enabling only flow 2 and a third flow from the evaporator 109 towards the junction
including,
The evaporator 109,
An integrated heat exchanger including a coil formed to alternate in a zigzag shape and a plurality of fins spaced apart at predetermined intervals to surround the coil;
a drain plate disposed below the integrated heat exchanger;
hot gas pipes alternately formed in a zigzag shape and connected in series to the heat exchanger;
a bypass connected in series with the heat exchanger and connected in parallel with the hot gas pipe; and
A control valve is installed in the bypass and controls the flow of the bypass by opening and closing, but the integrated heat exchanger includes an upper heat exchanger and a lower heat exchanger disposed below the upper heat exchanger to defrost the drain plate. and
During the defrosting operation of the refrigerator, the refrigerant flowing into the evaporator 109 first passes through the hot gas pipe and then is controlled to flow out of the evaporator 109 through the integrated heat exchanger. According to claim 1,
A liquid separator 106 connected to the first port of the compressor 105 between the first port of the compressor 105 and the confluence point 111, wherein the compressor 105 is operated during the freezing operation. A liquid separator (106) for flowing only gaseous refrigerant from among the refrigerant flowing toward the compressor (105) to the compressor (105) by collecting and evaporating liquid from the refrigerant flowing toward the compressor (105)
A defrost system further comprising a. According to claim 1,
The condenser 101 further includes a fan for assisting heat exchange,
During the defrosting operation of the refrigerator,
Characterized in that the fan of the condenser (101) is operated. According to claim 1,
During the defrosting operation of the refrigerator,
The expansion valve 110 enables a fourth flow from the condenser 101 toward the evaporator 109,
The four sides 112 allow only a fifth flow from the compressor 105 to the evaporator 109 and a sixth flow from the condenser 101 to the junction 111,
The flow direction of the fluid flowing in and out of the condenser (101) is opposite to the flow direction during the freezing operation, the defrosting system. According to claim 1,
During the freezing operation,
The control valve is opened so that the refrigerant flowing into the evaporator 109 is sequentially discharged from the evaporator 109 through the integrated heat exchanger and the bypass,
During the defrosting operation,
The control valve is closed so that the refrigerant flowing into the evaporator 109 in a direction different from that during the freezing operation sequentially flows out of the evaporator 109 through the hot gas pipe and the integrated heat exchanger. Defrosting system. According to claim 4,
The expansion valve 110 is an external equalization type bidirectional thermal expansion valve (TXV),
The defrosting system,
a temperature sensing means (113) installed between the first port of the compressor (105) and the confluence point (111) immediately adjacent to the first port to measure the temperature of the refrigerant upstream of the compressor (105);
a second capillary tube 114 connecting the temperature sensing means 113 and the expansion valve 110 to each other; and
To connect a point immediately adjacent to the first port and the expansion valve 110 between the first port of the compressor 105 and the joining point 111 in order to measure the pressure of the refrigerant upstream of the compressor 105 Configured third capillary (115)
Further comprising a defrost system. According to claim 1,
a second line connecting between the four sides (112) and the joining point (111) and between the four sides (112) and the compressor (105); and
As a pressure equalization valve 116 installed on the second line, it is opened when the compressor 105 stops to make the pressure upstream of the compressor 105 and the pressure downstream of the compressor 105 equal to each other, but the compressor ( 105) is a valve that remains closed when not stopped, a pressure equalization valve 116
A defrost system further comprising a. According to claim 7,
The defrosting entry in which the defrosting system switches from the freezing operation to the defrosting operation of the refrigerator, and the defrosting end in switching from the defrosting operation to the freezing operation are performed by switching the flow direction of the four sides 112,
Prior to the switching, the compressor 105 is stopped and the pressure equalization valve 116 is opened to equalize the pressure upstream of the compressor 105 and the pressure downstream of the compressor 105 for a predetermined waiting time. , The defrosting system, characterized in that the switching is performed. According to claim 1,
A high-low pressure switch 117 configured to stop the compressor 105 when at least one of the pressure upstream of the compressor 105 and the pressure downstream of the compressor 105 is lower than a preset lower limit value or higher than a preset upper limit value Defrost system further inclusive.

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