JP3197634B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a refrigeration system.

[0002]

2. Description of the Related Art A conventional refrigerating apparatus of this kind is configured as shown in FIG. In the figure, 1 is a compressor such as a scroll compressor, 2 is a condenser, 3 is a receiver, 4 is a decompression device such as an expansion valve, 5 is an evaporator, 6 is an accumulator,
These are connected by pipes 7a to 7f, respectively, to constitute a refrigeration system. A liquid injection pipe 8 is connected between the liquid receiver 3 and the compressor 1 via a solenoid valve 9. The conventional refrigeration system is composed of the above components 1 to 9. The refrigerant turned into vapor by the evaporator 5 enters the compressor 1 through the accumulator 6 and is compressed by the compressor 1 before being compressed. In the process, heat is taken by surrounding water or air and liquefaction occurs. The liquefied refrigerant enters the liquid receiver 3, passes through the pressure reducing device 4, enters the evaporator 5, and performs one cycle. Hereinafter, similarly, the refrigerant repeatedly circulates through the refrigeration cycle. During this time, the solenoid valve 9 is opened together with the operation of the refrigeration apparatus, and a part of the liquid refrigerant in the receiver 3 is supplied to the compressor 1 through the liquid injection pipe 8, and the heat of evaporation of the liquid refrigerant causes the compressor The first refrigerant is cooled.

[0003]

However, the prior art has the following problems due to its configuration. During the operation of the refrigeration system, the refrigerant supplied from the receiver 3 to the liquid injection pipe 8 is subjected to gas-liquid mixing due to a change in pressure of the refrigerant circulating in the pipe connecting the above-described elements and a change in ambient temperature. If the refrigerant is supplied as it is, such a refrigerant is likely to evaporate, so that the refrigerant evaporates in the liquid injection pipe 8 on the inlet side of the compressor 1, and the refrigerant flowing into the compressor decreases, and the refrigerant is compressed. Machine 1
Temperature rises abnormally. Also, when the amount of the circulated refrigerant is insufficient, the amount of the liquid refrigerant supplied to the liquid injection pipe 8 is insufficient, so that the temperature of the compressor abnormally rises as in the case described above. When the temperature of the compressor 1 rises and the temperature becomes abnormal, a protection operation mechanism (not shown) is activated and the operation of the compressor 1 is immediately stopped. In this case, the protection operation mechanism is automatically activated. Since the protection operation mechanism is activated when the refrigerant is insufficient, the ON / OFF operation is repeated even if the shortage has not been released. When the compressor 1 is a scroll compressor, the scroll teeth are damaged, and in other compressors, the sliding surface between the cylinder and the piston is burned and damaged, so that a so-called galling phenomenon occurs. . An object of the present invention is to provide a refrigeration apparatus for solving the above-mentioned problems (problems) of a conventional device.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems (problems) of the prior art, the present invention provides temperature sensors on the inlet and outlet sides of a liquid injection pipe, respectively. It is configured to detect an abnormal state in the liquid injection tube by comparing the detected values. In this case, it is desirable that an alarm be issued based on the detected value of the abnormal state by the temperature sensor, and that a necessary protection operation be performed based on the alarm.

[0005]

In the refrigerating apparatus of the present invention, temperature sensors are provided at the inlet side and the outlet side of the liquid injection pipe, respectively, and the temperature change of the liquid injection pipe is monitored. If an abnormal condition occurs, such as when the liquid refrigerant is supplied in a liquid mixed state or the amount of circulated refrigerant is insufficient, the liquid refrigerant is likely to evaporate in the liquid injection pipe circuit, so the outlet side of the receiver is The temperature difference between the compressor and the compressor inlet is larger than usual. This state is immediately detected by comparing the detection values of the two temperature sensors, and an alarm is issued.
Therefore, the necessary protective action is performed based on this alarm, so that the compressor temperature may rise abnormally or the compressor may be damaged due to operation with insufficient refrigerant. Is prevented.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to an embodiment shown in FIG. 1, components corresponding to those of the related art are denoted by the same reference numerals as in FIG. 10
And 11 are first and second temperature sensors, respectively. The first temperature sensor 10 is on the inlet side (outlet) of the liquid injection pipe 8, and the second temperature sensor 11 is on the outlet side of the liquid injection pipe 8. (Compressor inlet). Reference numeral 12 denotes the first and second temperature sensors 1
The controller 12 receives the detection signals from 0 and 11, and the controller 12 compares the above detection signals. When the difference becomes a predetermined value or more, the controller 12 sends an abnormal state detection signal to the alarm device 13, The alarm 13 issues an alarm. Although not shown, when an alarm signal is output from the alarm 13, the operation panel (FIG. 1) is operated by a maintenance operation of an official or by a maintenance operation automatically performed by a protection operation mechanism that operates in response to the alarm signal. (Not shown), the operation of the compressor 1 is stopped, and the refrigerant charge is stopped.
It is assumed that a maintenance operation such as a page is performed. 1
4 is a pressure reducing valve for a liquid injection pipe, 15 is a third temperature sensor provided in the pipe 7a on the outlet side of the compressor 1, and a detection signal of the third temperature sensor 15 is used for controlling the opening of the pressure reducing valve 9. You.

In the refrigerating cycle, as in the prior art, the refrigerant turned into vapor by the evaporator 5 is compressed by the compressor 1 through the accumulator 6 and then condensed and liquefied by the condenser 2, as in the conventional refrigeration cycle. The liquefied refrigerant is supplied to the receiver 3, the pressure reducing device 4
After that, a refrigeration cycle of leading to the evaporator 5 is repeatedly circulated. During this time, the solenoid valve 9 is opened together with the operation of the refrigeration apparatus, and a part of the liquid refrigerant in the receiver 3 is supplied to the compressor 1 through the liquid injection pipe 8, and the heat of evaporation of the liquid refrigerant causes the compressor The temperature of the discharged refrigerant is reduced. By the way, in the refrigerating apparatus of the present invention, the first and second temperature sensors 10 and 11 are provided on the inlet side and the outlet side of the liquid injection pipe, respectively, so that the temperature change of the liquid injection pipe 8 is monitored.
For example, the refrigerant supplied from the liquid receiver 3 is in a gas-liquid mixed state due to a change in the pressure in the pipe or a change in the ambient temperature, or the amount of refrigerant circulating in each pipe is insufficient and the liquid from the liquid receiver 3 If an abnormal state occurs in which the amount of refrigerant supplied to the liquid injection 8 is insufficient, the liquid refrigerant is likely to evaporate in the liquid injection pipe 8 circuit, and the amount of liquid refrigerant supplied to the compressor becomes insufficient. The abnormal temperature rise of the compressor is caused by the fact that the temperature difference between the outlet of the receiver and the inlet of the compressor is expanded more than usual by evaporation of the liquid refrigerant, and the temperature sensors 10 and 11 are used. An abnormality is detected by the controller 12 and the controller 12, and the alarm 13 issues an alarm indicating the abnormal state. Therefore, based on this alarm signal, manual maintenance operations by maintenance personnel
Alternatively, the operation of the compressor 1 is stopped by automatic operation by a separately provided protection operation mechanism, and required maintenance work such as charging of the refrigerant is performed. The adverse effects associated with continuing operation of the refrigeration system when the amount of refrigerant is insufficient are prevented beforehand.

[0008]

Since the present invention is configured as described above,
It has the following excellent effects. If the temperature of the compressor rises abnormally because the refrigerant supplied to the liquid injection pipe is in a gas-liquid mixed state or the refrigerant supplied to the liquid injection pipe is insufficient, the temperature sensor Since the controller detects an abnormal state based on the detection signal and issues an alarm, a necessary measure can be taken by the alarm signal before the protection operation function is activated. For this reason, the temperature of the compressor does not reach an abnormal temperature, and the operation of the compressor is continued in a state in which the amount of the refrigerant is insufficient, and the scroll teeth and the like are damaged by seizure such as galling. Such adverse effects can be prevented beforehand.

[Brief description of the drawings]

FIG. 1 is a refrigerant system diagram showing one embodiment of the present invention.

FIG. 2 is a refrigerant system diagram showing a configuration of a conventional example.

[Explanation of symbols]

 1: Compressor 2: Condenser 3: Liquid receiver 4: Decompression device 5: Evaporator 8: Liquid injection tube 10, 11: Temperature sensor 12: Controller 13: Alarm

(72) Inventor Hidekazu Hashizume 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Mitsuo Hagiwara 2--18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. In-company (56) References JP-A-2-10057 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 1/00 F25B 49/02 570

Claims (2)

(57) [Claims] 1. A compressor, a condenser, a liquid receiver, a pressure reducing device, an evaporator, and the like are connected by piping, and a liquid refrigerant in the liquid receiver is supplied to the compressor between the liquid receiver and the compressor. In a refrigeration system to which a liquid injection pipe is connected, temperature sensors are provided on the inlet side and the outlet side of the liquid injection pipe, respectively, and by comparing the detection values of these temperature sensors, an abnormal state in the liquid injection pipe is determined. A refrigeration apparatus characterized in that it is detected. 2. The refrigerating apparatus according to claim 1, wherein an alarm is issued based on a detected value of the abnormal state by the temperature sensor, and a required protection operation is performed based on the alarm.