JPS58148360A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration system, and particularly to an operation control circuit suitable for a refrigeration system that performs hot gas defrosting.

The hot gas defrost system that is currently widely used is a simple hot gas defrost system as shown in Figure 's1. In the figure, solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and broken line arrows indicate the m flow n direction of the refrigerant during the defrosting operation. In the defrosting operation, the liquid solenoid valve 5 and the hot gas solenoid valve 6f are switched to flow the refrigerant as indicated by the broken line arrow. When defrosting is finished, both solenoid valves are switched again and cooling operation begins. However, at this time, J[Ai! i}4
If a large amount of liquid refrigerant is loaded into the Q1 and the cooling operation is immediately started, a liquid back-up will occur, and accidents such as pulp damage and metal burnout in the compressor are likely to occur.

The purpose of this book 9 is to provide a refrigeration system that smoothly switches to cooling operation in 4 lines by eliminating the liquid back-up that occurs when switching from defrosting operation to cooling operation as in simple hot gas defrosting. be.

Liquid back-up occurs only when liquid refrigerant remains in the evaporator at the start of cooling operation, and if there is no liquid refrigerant, liquid back-up will not occur. Therefore, it is sufficient to darken the liquid refrigerant remaining in the evaporator at the end of frosting, and then start the cooling operation. To this end, the present invention is characterized in that after the vibration is removed, the liquid refrigerant in the evaporator is recovered into the condenser by the bongdakun operation, and then the cooling operation is started.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 shows a cycle system diagram of a refrigeration system that performs simple hot defrosting and dew removal similar to the prior art. FIG. 2 shows an embodiment of a control circuit diagram according to the present invention. A low pressure switch 7 is connected in series to the compression electromagnetic switch 8 to control starting and stopping of the compressor. 9 is a defrosting timer Ω, whose contact 9C is held at the position shown in the figure during cooling operation, and the contact is switched for defrosting once every few hours.

10 is the coil of the liquid solenoid valve 5, 11 is the hot gas solenoid valve 6
The coil is connected to both poles of the X contact 9C to switch the opening and closing of each solenoid valve during cooling operation and defrosting operation.

Reference numeral 12 denotes a thermostat that opens and closes by checking the temperature inside the freezer. When the temperature inside the freezer is high, it is closed as shown in the figure, but when it becomes low, the liquid electromagnetic valve coil 10 is demagnetized and the liquid electromagnetic valve is closed. The valve 5 is closed and the refrigerant in the evaporator 4 is recovered to condensate a2 by pumping down, and the low pressure drain 1 is opened due to the drop in the low pressure pressure, and the compressor 1 is stopped.

When the contact point 9C of the steam timer 9 is turned to the defrosting side, the liquid solenoid valve 5 closes, the hot gas valve 6 turns on, and the refrigerant gas discharged from the compressor 1 evaporates! 4, it is condensed and liquefied due to the carbon removal action, and a part of it is returned to the pressure LiA machine 1.
The heat is evaporated and the compressor is closed. One-line electromagnetic fPW is Ii! on the cooling side of contact 9C! The contact +32 of the delay timer 13, which is set to 3 minutes, is open and the defrosting end is closed. Since the low pressure is high for defrosting 1, compression IA1 continues to operate, and while liquid electromagnetic box 5 is closed, pump-down operation is performed to recover liquid refrigerant from evaporator 4 to #im unit 2. will be carried out. F
7 to 111IIr 03 minutes to 4 minutes, the refrigerant recovery is completed and the contact point +32 of the delay timer 13 closes, so the liquid solenoid valve 5 opens at this point. It passes through the 1# converter 3 and enters the evaporator 64, where one cooling cycle is started.

As mentioned above, after defrosting is completed, only the gas solenoid valve is switched, and the liquid solenoid valve is closed for 3 minutes.During this period, pump down operation is performed to remove the evaporated liquid refrigerant. In order to collect the
The cooling operation can be smoothly shifted to 4C soap 111J&Th without causing any liquid back up.

As explained above, according to the present invention, since the pump down operation is performed when transitioning from defrosting operation to cooling operation, there is no liquid buildup in the compressor and smooth operation is achieved.
It has the effect of being 11m long.

[Brief explanation of the drawing]

FIG. 1 is a cycle system diagram of a refrigeration system that performs simple hot gas defrosting according to an embodiment of the present invention, and FIG. 12 is a control circuit diagram of the refrigeration cycle of FIG. 5... Liquid solenoid valve 6... Hot gas solenoid valve 13.
...Delay timer 13a...Delay timer contact substitute field Patent attorney Susuki 1) Rise (5\

Claims (1)

[Claims] A refrigeration system that performs hot gas defrosting, characterized in that a refrigerant in an evaporator is recovered into a condenser by post-defrost control, and then refrigeration operation begins.