JPH0212353B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of the Invention The present invention relates to a refrigeration system that introduces refrigerant compressed by a compressor from a condenser into an evaporator through a capillary tube, and heats the evaporator with a heater to defrost the evaporator. .

(b) Background technology The refrigerant compressed by the compressor is introduced from the condenser into the evaporator through the capillary tube, and the evaporator is heated by a heater to defrost the compressor while the operation of the compressor is stopped and the defrosting operation is completed. When starting the compressor, a bypass refrigerant circuit with a solenoid valve that connects the discharge side and suction side of the compressor while the compressor is stopped and closes when the compressor starts is used to reduce the starting load on the compressor. Some systems have a solenoid valve installed on the suction side of the compressor and are closed for a short time when the compressor starts, but these require a solenoid valve with a moving part and a relay circuit to control it, which can lead to failures. There are drawbacks that arise.

(C) Purpose of the Invention The present invention aims to reduce the load at the time of starting the compressor after defrosting the evaporator by heating it with a heater, improve the cooling efficiency, and improve the efficiency of the defrosting operation. With the goal.

(D) Embodiment of the invention 1 is an electric compressor, 2 is a condenser, 3 is a dehydrator, 4 is a capillary tube, 5 is a refrigerant tank, and 6 is an evaporator, which are connected in series as shown in Figure 3. refrigeration equipment. 7 is a two-temperature refrigerator body in which a freezer compartment 8 and a refrigerator compartment 9 are divided by a partition wall 10. An evaporator 6 is housed in a cold air passage in the partition wall 10, and the air cooled by the evaporator 6 is sent to an electric blower 11. It circulates to both chambers 8 and 9. The refrigerant tank 5 is housed in the back wall of the main body 7 so as to be covered with a cool storage agent 12 housed in a suitable bag and buried in the heat insulating material 1A of the main body 7. The relationship between the refrigerant tank 5, the evaporator 6, and the capillary tube 4 is as shown in detail in FIG.
is in communication with the bottom of the refrigerant tank 5, and the outlet end of the capillary tube 4 is connected to the lower end of the tank 5 together with the end of the inlet pipe 13 so that the outlet end of the capillary tube 4 opens into the inlet pipe 13. is welded to. One end of a refrigerant inflow pipe 14 into the tank 5 communicates with the upper part of the tank 5, and the other end of the pipe 14 communicates with an intermediate portion of the inlet pipe 13. Reference numeral 15 denotes a check valve provided in the pipe 14, which acts to open a refrigerant passage for the flow of refrigerant from the inlet pipe 13 to the tank 5, and to close the passage for the opposite flow. The cool storage agent 12 is used in the evaporator 6 in a normal cooling operation cycle, that is, in a cycle in which the electric compressor 1 is stopped by the temperature controller of the refrigerator.
(e.g., a freezing point higher than -20°C). 16 is a suction pipe connecting the evaporator 6 and the compressor 1, through which a part of the capillary tube 4 is inserted.

In this configuration, in the cooling operation cycle, refrigerant circulates through the electric compressor 1 - condenser 2 - dehydrator 3 - capillary tube 4 - evaporator 6 - electric compressor 1. When defrosting is performed by heating the evaporator 6 by generating heat from the electric heater, the temperature and pressure inside the evaporator 6 rise. The refrigerant tank 5 is maintained at the temperature of the refrigerant 12 cooled in the cooling operation cycle, and the inside of the tank 5 is maintained at a saturated vapor pressure corresponding to the temperature maintained by the refrigerant 12. When the temperature of the evaporator 6 rises above the temperature of the cool storage agent 12, the refrigerant in the evaporator 6 flows into the refrigerant tank 5 and is condensed. At this time, the refrigerant initially flows into the tank 5 from the lower and upper parts of the tank 5 through the pipes 13 and 14, but when the inner bottom of the tank 5 is filled with liquid refrigerant, it begins to flow only from the pipe 14. Since the gas refrigerant does not pass through the liquid refrigerant, the refrigerant noise that occurs at that time is eliminated. When the defrosting operation is completed by stopping the power supply to the heater, the pressure inside the evaporator 6 is maintained at the saturated vapor pressure of the refrigerant corresponding to the temperature of the cold storage agent 12,
2 to 3 kg/more than when the refrigerant tank 5 does not exist.
cm ² G pressure can be lowered, reducing the load when restarting the electric compressor 1 after defrosting. When the electric compressor 1 starts, the check valve 15 closes, so the liquid refrigerant in the tank 5 quickly flows from the bottom of the tank 5 through the pipe 13 to the evaporator 6, and the evaporator 6 can be cooled quickly. , the inside of the refrigerator main body 7 is quickly cooled down. Since the outlet end of the capillary tube 4 is opened into the pipe 13, the liquid refrigerant leaving the capillary tube 4 does not accumulate in the tank 5 during cooling operation, so that the liquid refrigerant can be used effectively in the evaporator 6. It is something that can be done. If the outside of the tank 5 is covered with the cold storage agent 12 and then covered with a heat insulating material, the effect will not change even if the tank 5 is covered with a different heat insulating material when used in applications other than refrigerators.

(E) Effects of the Invention In the present invention, during the defrosting operation in which the evaporator is heated by a heater, the refrigerant in the evaporator flows into the refrigerant tank, condenses and accumulates, and when the cooling operation is restarted, the liquid refrigerant in the tank evaporates. This allows the evaporator to be effectively heated during the defrosting operation, and improves the startability of the electric compressor when the cooling operation is resumed after the defrosting operation is completed. This improves efficiency. Note that by not opening the outlet end of the capillary tube into the tank, it is possible to prevent refrigerant noise during defrosting operation.

[Brief explanation of drawings]

Each figure shows an embodiment of the present invention; FIG. 1 is a longitudinal sectional side view of a two-temperature refrigerator, FIG. 2 is a sectional view of a refrigerant tank, and FIG. 3 is a refrigerant cycle diagram of a refrigeration system. 1... Electric compressor, 2... Condenser, 4... Capillary tube, 5... Refrigerant tank, 6... Evaporator, 12...
Cold storage agent, 13... Evaporator inlet pipe, 14... Pipe, 15... Check valve.

Claims (1)

[Claims] 1. Introduce the refrigerant compressed by the compressor from the condenser to the evaporator through the capillary tube, and at the same time generate heat in the electric heater to heat the evaporator and defrost it. After defrosting is completed, restart the compressor. A refrigerant tank is provided in which the inlet pipe of the evaporator communicates with the lower part and the middle part of the inlet pipe communicates with the upper part, and the pipe which communicates the middle part of the inlet pipe with the upper part of the refrigerant tank includes: A check valve is provided to open a passage for the flow of refrigerant from the inlet pipe to the refrigerant tank and prevent the reverse flow, and the tank is covered with a refrigerant and then covered with a heat insulating material. Refrigeration equipment.