JP2604501Y2 - Cooling unit with abnormality detection switch - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to improving the reliability of the operation of showcases in refrigerated warehouses and supermarkets, and to simplifying electric work.

[0002]

2. Description of the Related Art Conventionally, in a refrigerating apparatus in which a refrigerator and a cooling unit are installed at a remote place, and a refrigerant pipe is connected between the refrigerator and the cooling unit, when the refrigerator becomes inoperable due to an abnormality in the refrigerator, cooling is performed. The unit goes into defrosting operation,
In order to prevent a large amount of liquid refrigerant from accumulating on the low pressure side, an electric wire for operation is connected between them, and the defrost heater and the cooling control solenoid valve are stopped. In addition, the conventional cooling control solenoid valve is controlled only by a thermostat or an operation timer, and there is no upper limit for the pressure of the low-pressure side refrigerant of the cooling unit. It was easy. To prevent this, a suction pressure regulating valve and suction accumulator were installed on the refrigerator side. The cooling unit referred to here is a unit containing an evaporator,
Includes refrigerated and frozen showcases. Further, the switch referred to in this specification electrically switches the operation, and includes a switch made of a semiconductor having no contact.

[0003]

[Problem to be solved by the invention] Laying operation electric wiring at the site construction increases construction cost,
There was a demand for elimination of the wiring itself, as there were many incorrect wirings.However, if the wiring was lost without doing anything, the refrigerator and cooling unit would operate arbitrarily. When there is a large amount of liquid refrigerant accumulated in the cooling unit, when the refrigerator is repaired and the operation is resumed, the liquid refrigerant may be sucked at a time and cause a failure such as a crack in the valve of the compressor again. is there. In addition, since the defrost timer is provided on the cooling unit side, even if the refrigerator is out of order, the defrost operation will be performed as it is, and the temperature inside the refrigerator will rise sharply because the defrost heater is turned on. Has led to the rotting of their products. The present invention has been made to eliminate the need for construction of operation wires on site and to ensure safe operation.

[0004]

SUMMARY OF THE INVENTION A pressure sensor (1) is attached to a low pressure side pipe (5) of a cooling unit, and an abnormality detection switch (7) operated by the pressure sensor is connected to a cooling control solenoid valve (2). And a cooling unit incorporating an electric circuit for operation incorporated in the circuit of the defrost heater (3). The operating pressure of the abnormality detection switch (7) is set to an intermediate pressure between the refrigerant pressure corresponding to the set temperature in the refrigerator and the cut-in set pressure of the low-pressure switch (17) for operating the refrigerator. When the pressure of the gas in the low pressure side pipe (5) rises to the cut-in set pressure of the low pressure switch for operation (17), the operation of the refrigerator starts the compressor (14) and drops below the cut-out set pressure. Then, a pump-down circuit for stopping the compressor (14) is provided. In addition, the pressure sensor referred to in this specification includes a pressure sensor, a pressure sensing mechanism of a pressure switch, and a strain sensor.

[0005]

The thermostat (9) for setting the temperature of the refrigerator is activated, the solenoid valve (2) for cooling control is opened, and the refrigerant gas is supplied to the cooler (4). If there is no abnormality in the compressor and it is operating normally, the compressor (14) is started before the abnormality detection switch (7) is operated, and the pressure starts to decrease. When there is an abnormality on the refrigerator side and the operation cannot be performed, the low pressure continues to increase beyond the cut-in set pressure of the operation low pressure switch (17). Then, the abnormality detection switch (7) mounted on the cooling unit side is operated, and the cooling control solenoid valve (2) supplying the refrigerant gas to the cooler (4) is closed, and the cooler (4) To prevent accumulation of the liquid refrigerant in the air. Further, by operating the abnormality detection switch (7), the circuit for defrosting is shut off so that heating by the defrosting heater (3) is prevented.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A pressure sensor (1) is attached to a low-pressure pipe (5) which will be described below with reference to an embodiment. An abnormality detection switch (7) operated by the pressure sensor (1) is connected to a solenoid valve (2) for cooling control. And in the circuit of the defrost heater (3)
Cooling unit with built-in operation circuit. At the time of construction on site, the refrigerator and the cooling unit separately installed are connected by refrigerant pipes, and power is supplied only to the refrigerator and the cooling unit, so that electrical work related to operation is not required.

[0007]

[Effects of the Invention] Electrical work of a separately installed refrigeration facility is simplified, and erroneous wiring is reduced. Also, the liquid bag operation is reduced, and the reliability of the refrigeration equipment is increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment.

FIG. 2 is a refrigerant system diagram showing a first embodiment.

FIG. 3 is a refrigerator operation circuit diagram showing the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure sensor 2 Cooling control solenoid valve 3 Defrost heater 4 Cooler 5 Low pressure side pipe 6 High pressure side liquid pipe 7 Abnormality detection switch 8 Expansion valve 9 Cooling control thermostat 10 Cooler fan 11 Defrost timer 12 Overheat prevention switch 13 Contactor for defrost heater 14 Compressor 15 Condenser 16 Liquid receiver 17 Low pressure switch for operation 18 Magnet switch for compressor

Claims (1)

(57) [Scope of request for utility model registration] In a cooling unit of a refrigeration system in which a cooling unit installed at a different place from a refrigerator operated by a pump-down circuit is connected by a refrigerant pipe, a pressure sensor (1) is connected to a low pressure side pipe (5). The malfunction detection switch (7) operated by the pressure sensor (1) is incorporated in the operation circuit, and the operating pressure value of the malfunction detection switch (7) is set to the activation set pressure of the low pressure switch (17) for operating the refrigerator. When the pressure of the low pressure side pipe (5) rises above the activation set pressure value of the low pressure switch (17) for operation of the refrigerator when the pressure is set to the pressure value or more and the refrigerator cannot operate due to an abnormality in the refrigerator. , A cooling unit with an abnormality detection switch characterized by switching to an operation when the refrigerator cannot be operated "