JP3621739B2 - refrigerator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a refrigerator, and more particularly to prevention of low-pressure operation that occurs during transient operation of starting a compressor after defrosting.
[0002]
[Prior art]
The conventional refrigerator has a structure as known in Japanese Utility Model Laid-Open No. 3-83791. Hereinafter, the configuration of a conventional refrigerator will be described with reference to FIG.
[0003]
1 is a high-pressure vessel type compressor, 2 is a condenser, 3 is a capillary tube, 4 is an evaporator, and the compressor 1, the condenser 2, the decompression device 3, and the evaporator 4 are sequentially connected in an annular manner, and the refrigeration cycle is performed. Forming. Reference numeral 5 denotes a main body of the refrigerator, which divides the inside and forms two rooms, a freezer compartment 6 and a refrigerator compartment 7, respectively. A defrosting heater 8 is provided in the vicinity of the evaporator 4.
[0004]
9 detects the time interval set in advance by the defrosting detecting means, the temperature of the evaporator 4 and the frosting state, and detects the end of defrosting during the defrosting operation. The defrost control means (not shown) controls the operation and stop of the compressor 1 and the operation stop of the defrost heater 8 by the detection output of the defrost detection means 9.
[0005]
Reference numeral 10 denotes a water pipe that guides the defrost water to the evaporating dish 11. The evaporating dish 11 is in the machine chamber 12, and a part of the condenser 2 is disposed in the evaporating dish 11. A part near the discharge of the compressor 1 is usually used as a part of the condenser 2 in order to improve the evaporation efficiency.
[0006]
Next, the operation of the conventional configuration will be described.
The high-temperature and high-pressure refrigerant discharged from the compressor 1 by the operation of the compressor 1 is condensed and liquefied by the condenser 2, further depressurized by the capillary 3, evaporated by the evaporator 4, and heated by heat transfer means (not shown). The freezer compartment 6 and the refrigerator compartment 7 are cooled. The refrigerant vaporized by the evaporator 4 is again sucked into the compressor 1.
[0007]
By performing such a cooling operation, moisture contained in the air in the freezer compartment 6 and the refrigerator compartment 7 adheres to the surface of the evaporator 4 as frost when heat is exchanged in the evaporator 4. As this frosting progresses, the heat exchange efficiency of the evaporator 4 decreases, and sufficient cooling operation becomes impossible.
[0008]
This state is detected by the defrost detection means 9 and outputs a defrost start signal to the defrost control means. Upon receiving this signal, the defrost detection means starts defrosting.
The defrosting control means stops the compressor 1, operates the defrosting heater 8, and starts defrosting. By operating the defrosting heater 8, the frost on the surface of the evaporator 4 is melted by heat generation.
[0009]
When the frost on the surface of the evaporator 4 is melted, the defrosting detecting means 9 detects that the defrosting is completed when the temperature of the normal evaporator 4 is equal to or higher than a predetermined temperature (generally 10 to 20 ° C.). The defrosting end signal is output to the defrosting control means. In response to this signal, the defrosting control means stops the defrosting heater 8 in order to end the defrosting operation, and then starts the compressor 1. By this operation, the refrigeration cycle starts the cooling operation again.
[0010]
The defrost water generated by the defrosting is sent to the evaporating dish 11 through the water pipe 10. The defrost water once stored in the evaporating dish is gradually evaporated by exchanging heat with a part of the high-temperature condenser 2 when the compressor 1 starts operation.
[0011]
[Problems to be solved by the invention]
However, in the above conventional configuration, at the low ambient temperature, in addition to the refrigerant held in the evaporator 4 immediately before the start of defrosting, at the same time as the compressor 1 is stopped, the ambient temperature of the condenser 2 and the compressor 1 and the evaporator The refrigerant starts to move from the compressor 1 and the condenser 2 to the evaporator 4 due to the refrigerant saturation pressure difference resulting from the difference in the ambient temperature of 4. When the temperature of the evaporator 4 rises due to the progress of defrosting, and the evaporator 4 and its ambient temperature become higher than the ambient temperature of the compressor 1 and the condenser 2, the refrigerant is saturated, contrary to the initial stage of the defrosting operation. The pressure is higher in the evaporator 4, and the refrigerant moves from the evaporator 4 to the compressor 1 and the condenser 2.
[0012]
At the end of defrosting, the refrigerant in the evaporator 4 almost disappears and remains ubiquitously in the condenser 2 having the lowest temperature during the refrigeration cycle. In particular, it is ubiquitous in some condensers cooled by low-temperature defrost water.
[0013]
For this reason, at the time of starting the compressor 1 after defrosting, the refrigerant is not the refrigerant distribution state in the condenser 2 in the normal operation stable state, that is, the state from the gas phase to the liquid phase from the compressor 1 toward the capillary 3. It stays and there is almost no refrigerant in the evaporator 4.
[0014]
For this reason, when the compressor 1 is started, since there is almost no refrigerant in the evaporator 4, the specific volume of the suction gas is small and it cannot be pressurized sufficiently. At the same time, since the refrigerant is ubiquitous in the condenser 2, the liquid refrigerant does not reach the inlet of the capillary tube 3 stably, and a large amount of gas is caught in the capillary tube 3, thereby inhibiting the circulation of the refrigerant. Due to this vicious cycle, a low-pressure operation state occurs in which the balance of the refrigeration cycle is lost in the operation transition period after defrosting.
[0015]
The sliding of the compressor 1 continues in a low pressure operation in which the refrigerant and the lubricating oil circulating with the refrigerant return little while the oil film of the sliding portion of the compressor 1 is cut off due to liquid return or the like in the startup transition period. The part became dry friction and abnormal wear occurred, which was a very big problem from the viewpoint of the reliability of the compressor 1.
[0016]
Furthermore, it takes time until the refrigeration cycle is stabilized after startup, leading to an increase in power consumption due to an increase in operating time.
[0017]
The refrigerator of this invention solves the conventional subject, and it aims at providing the refrigerator which can prevent the low voltage | pressure operation at the time of the compressor starting after a defrost.
[0018]
[Means for Solving the Problems]
A high-pressure vessel type compressor, a condenser, a capillary that is a decompression means, and a refrigeration cycle in which an evaporator is sequentially connected in an annular manner are installed, and a chamber is provided between the capillary and the condenser. A defrosting heater provided in the vicinity of the evaporator, a defrosting detecting means for detecting completion of defrosting of the evaporator, a defrosting water tray for storing defrosted water, and the defrosting water in the defrosting water dish The chamber is arranged such that the water pipe to be led and the defrosting water tray are located in the lower part of the defrosting water dish so that the connection part with the capillary is on the lower part.
[0019]
[Action]
With the above configuration, in the refrigerator of the present invention, defrost water generated by defrosting is stored in a defrost water tray through a water pipe. At this time, the chamber located below the defrost water tray and a part of the capillary inlet are immersed in the defrost water and cooled.
[0020]
Thereby, the refrigerant in the evaporator moves to the cooled chamber due to the rise of the evaporator temperature during defrosting, and at the end of the defrosting, the refrigerant exists in the chamber and the capillary inlet, Since the connecting portion between the chamber and the capillary is located below, the capillary inlet is in a liquid-sealed state.
[0021]
Therefore, when the compressor is started after defrosting, liquid refrigerant flows from the capillary into the evaporator, and the operation is performed without gas being caught, so that the transition to the stable state of the refrigeration cycle can be performed smoothly, and the low pressure operation occurs. Absent.
[0022]
【Example】
An embodiment of the present invention will be described with reference to FIG. However, the same reference numerals are given to the same components as those in the prior art, and detailed description thereof is omitted.
[0023]
1 is a high-pressure vessel type compressor, 2 is a condenser, 3 is a capillary tube, 4 is an evaporator, and the compressor 1, the condenser 2, the decompression device 3, and the evaporator 4 are sequentially connected in an annular manner, and the refrigeration cycle is performed. Forming. A chamber 13 is provided between the capillary tube 3 and the condenser 2. Reference numeral 5 denotes a main body of the refrigerator, which divides the inside and forms two rooms, a freezer compartment 6 and a refrigerator compartment 7, respectively. A defrosting heater 8 is provided in the vicinity of the evaporator 4.
[0024]
9 detects the time interval set in advance by the defrosting detecting means, the temperature of the evaporator 4 and the frosting state, and detects the end of defrosting during the defrosting operation. The defrost control means (not shown) controls the operation and stop of the compressor 1 and the operation stop of the defrost heater 8 by the detection output of the defrost detection means 9.
[0025]
Reference numeral 14 denotes a defrosting water tray for storing defrosted water generated at the time of defrosting. The water pipe 10 guides the defrosted water to the defrosting water dish 14, and the capillary tube 3 is positioned below the defrosting water dish 14. The chamber 13 is disposed so that the connecting portion is on the lower side.
[0026]
Next, the operation of the conventional configuration will be described.
The cooling operation by the operation of the compressor 1 is performed, and frosting proceeds in the evaporator 4. Thereby, the heat exchange efficiency of the evaporator 4 decreases, and sufficient cooling operation becomes impossible.
[0027]
This state is detected by the defrost detection means 9 and outputs a defrost start signal to the defrost control means. Upon receiving this signal, the defrost detection means starts defrosting.
The defrosting control means stops the compressor 1, operates the defrosting heater 8, and starts defrosting. By operating the defrosting heater 8, the frost on the surface of the evaporator 4 is melted by heat generation.
[0028]
When the frost on the surface of the evaporator 4 is melted, the defrosting detecting means 9 detects that the defrosting is completed when the temperature of the normal evaporator 4 is equal to or higher than a predetermined temperature (generally 10 to 20 ° C.). The defrosting end signal is output to the defrosting control means. In response to this signal, the defrosting control means stops the defrosting heater 8 in order to end the defrosting operation, and then starts the compressor 1. By this operation, the refrigeration cycle starts the cooling operation again.
[0029]
The defrost water generated by the defrost is sent to the defrost water tray 14 through the water pipe 10 and stored. At this time, the chamber 13 located below the defrosting water tray 14 and a part of the inlet of the capillary tube 3 are immersed in the low-temperature defrosting water and cooled.
[0030]
As a result, the refrigerant in the evaporator 4 moves to the cooled chamber 13 according to the evaporator temperature during defrosting, and at the end of the defrosting, the refrigerant exists at the inlet of the chamber 13 and the capillary tube 3. And the capillary 3 are located below, so that the capillary 3 inlet is in a liquid-sealed state.
[0031]
Therefore, when the compressor 1 after defrosting is started, the liquid refrigerant flows from the capillary tube 3 to the evaporator 4 and operates without the gas being caught, so that the transition to the stable state of the refrigeration cycle can be performed smoothly, and the low pressure operation can be performed. Does not happen.
[0032]
Since there is no low-pressure operation in the start-up transition period, the lubricating oil circulating with the refrigerant returns, so the sliding portion of the compressor 1 does not become dry friction, and abnormal sliding of the compressor 1 occurs. Therefore, the reliability of the compressor 1 can be ensured.
[0033]
Furthermore, since it takes no time until the refrigeration cycle is stabilized after startup, the operation time is shortened and the power consumption is reduced.
[0034]
In the case where a dryer is provided between the condenser 2 and the capillary tube 3, the same effect can be expected even if the dryer is also used as the chamber 13, and the parts cost can be rationalized.
[0035]
In addition, the defrosting detection means 9 may be, for example, a temperature detection device or an optical sensor using bimetal, and outputs a defrosting start signal every time a predetermined time elapses or every time the predetermined compressor 1 accumulated operation time elapses. It may be a timer.
[0036]
【The invention's effect】
As apparent from the above description, the refrigerator of the present invention is provided with a refrigeration cycle in which a high-pressure container compressor, a condenser, a capillary tube as a decompression means, and an evaporator are sequentially connected in an annular manner, A chamber is provided between the capillary tube and the condenser, a defrosting heater provided in the vicinity of the evaporator, a defrosting detecting means for detecting completion of defrosting of the evaporator, and a defrosting water storage unit. A frost water tray, a water pipe that guides defrost water to the defrost water tray, and the chamber disposed so as to be positioned below the defrost water tray and connected to the capillary. Since equipped with, liquid refrigerant flows into the evaporator from the capillary when starting the compressor after defrosting, so that the operation without gas biting can smoothly transition to the stable state of the refrigeration cycle, Low pressure operation does not occur.
[0037]
Since there is no low-pressure operation in the start-up transition period, the lubricating oil circulating with the refrigerant returns immediately, and the sliding part of the compressor 1 does not become dry friction, so that abnormal sliding of the sliding part of the compressor 1 occurs. Therefore, the reliability of the compressor 1 can be ensured.
[0038]
Furthermore, since it takes no time until the refrigeration cycle is stabilized after startup, the operation time is shortened and the power consumption is reduced.
[Brief description of the drawings]
FIG. 1 is a sectional view of a refrigerator according to an embodiment of the present invention. FIG. 2 is a sectional view of a conventional refrigerator.
DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Capillary 4 Evaporator 8 Defroster heater 9 Defrost detection means 13 Chamber 14 Defrost water dish

Claims (1)

A refrigeration cycle in which a high-pressure vessel type compressor, a condenser, a capillary as a decompression means, and an evaporator are sequentially connected in an annular manner is installed, and a chamber is provided between the capillary and the condenser. The defrosting heater provided in the vicinity of the evaporator, the defrosting detecting means for detecting the end of the defrosting of the evaporator, the defrosting water dish for storing the defrosting water, and the defrosting water for the defrosting water dish A refrigerator comprising: a water pipe to be led and a lower part in the defrosting water tray, wherein the chamber is disposed so that a connection portion with the capillary tube is downward.

Images