JPH07294073A - Refrigeration device - Google Patents

Abstract

PURPOSE:To prevent lowering of refrigerating capacity and occurrence of trouble of a compressor by surely detecting leakage of refrigerant. CONSTITUTION:A refrigeration device 10 is basically constituted of a compressor 12, a condenser 14, an expansion valve 16, and an evaporator. A high pressure switch 30 for sensing high pressure is inserted into a refrigerant delivery pipe 28 of the compressor 12. The switch 30 is actuated when high pressure falls below a set pressure due to leakage of refrigerant to input a sensing signal into a control means 32. A temperature sensor 34 is provided at a refrigerant outlet pipe 26 of the condenser 14 and the sensor 34 is connected to the control means 32. The sensor 34 is actuated when it senses a temperature higher than a saturation temperature at a set pressure of the switch 30 to input a sensing signal into the control means 32. Even if the switch 30 is in unactuated state, the means 32 stops the operation of the compressor 12 when it receives the sensing signal from the sensor 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus used in a refrigerator, an ice making machine, or the like, and more specifically, it detects a leakage of a refrigerant to cause a decrease in cooling capacity or a failure of a compressor. The present invention relates to a refrigerating device which can be prevented.

[0002]

2. Description of the Related Art A refrigerating apparatus suitable for use in refrigerators and ice makers includes a compressor for compressing a refrigerant such as Freon, and a condenser for receiving a high-pressure / high-temperature vaporized refrigerant compressed by the compressor. An expansion valve to which the liquefied refrigerant condensed in this condenser is supplied, and an evaporator to which the refrigerant that has been expanded and vaporized through this expansion valve is supplied are basically provided. Then, the vaporized refrigerant whose temperature has risen due to heat exchange in the evaporator is returned to the compressor, and the refrigerant is compressed to high pressure and high temperature before being recycled.

In a refrigerating apparatus adopting, for example, a water cooling type as the condenser, the cooling water amount is increased when the high pressure becomes higher than a preset pressure so as to keep the high pressure of the refrigerant constant, and conversely, when the high pressure becomes lower. A condensing pressure control valve is provided to control the amount of water to reduce the amount of cooling water. In this case, when the refrigerant circulating in the refrigeration circuit leaks and causes a shortage of the refrigerant, the high pressure decreases, and the condensing pressure control valve reduces the amount of cooling water and finally stops the supply of cooling water. It was happening. In this case, the high-temperature gas is discharged without being dissipated in the condenser and circulates in the circuit, resulting in a decrease in the cooling capacity and a sudden overheating of the compressor, which causes seizure and other failures. There was a problem.

Therefore, conventionally, a temperature detecting sensor is provided on the refrigerant discharge side of the compressor, and the temperature rise of the discharged refrigerant due to the overheating operation of the compressor due to the shortage of the refrigerant is detected by the sensor to operate the compressor. It has stopped. When the refrigerant is insufficient, the pressure of the refrigerant returning from the evaporator (low pressure) decreases, so a pressure detection sensor is provided on the refrigerant suction side of the compressor, and the sensor detects the decrease in low pressure. The compressor is being shut down.

[0005]

In the refrigeration system, the temperature of the refrigerant discharged from the compressor may rise due to the overload of the refrigeration cycle even if refrigerant leakage does not occur. This temperature rise is detected and the compressor is erroneously stopped, resulting in a decrease in operating efficiency. If the refrigerant leaks, the high-pressure pressure of the refrigerant discharged from the compressor begins to decrease, and the temperature of the refrigerant begins to rise with a delay of the required time. It was difficult to do.

In the refrigerating apparatus, an expansion valve is arranged on the refrigerant inlet side of the evaporator, and the throttle control of the expansion valve is performed by a temperature sensitive cylinder provided on the refrigerant outlet side of the evaporator.
As described above, when high-temperature gas circulates in the circuit due to lack of refrigerant, the temperature sensing cylinder detects high temperature and shifts the expansion valve to the fully open state, so at the initial stage of refrigerant leakage, the refrigerant suction side of the compressor The low pressure of is almost the same as the case of normal operation, at which time the pressure detection sensor does not work,
No refrigerant leak could be detected. Then, when the leak amount of the refrigerant further increases and the low pressure decreases, the current situation is that the pressure detection sensor detects this. That is, at the time when the pressure detection sensor detects a decrease in the low pressure, the compressor has already been performing the overheat operation due to the shortage of the refrigerant for the required time, and the deterioration of the compressor cannot be avoided.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks inherent in the refrigerating apparatus according to the prior art described above, and has been proposed in order to suitably solve the drawbacks. It is an object of the present invention to provide a refrigerating device that can prevent a decrease in cooling capacity and a compressor from occurring.

[0008]

In order to solve the above-mentioned problems and preferably achieve the intended purpose, a refrigerating apparatus according to the present invention includes a compressor for compressing a refrigerant and a compressor for compressing the refrigerant. And a condenser that receives the supply of high-pressure and high-temperature vaporized refrigerant,
An expansion valve to which the liquefied refrigerant condensed in this condenser is supplied, an evaporator to which the refrigerant that has been expanded and vaporized through this expansion valve is supplied, and a pressure control valve that keeps the condensation pressure of the condenser constant In the refrigerating apparatus, the pressure detecting means for detecting the high pressure on the refrigerant discharge side of the compressor, the temperature detecting means for detecting the refrigerant temperature on the refrigerant outlet side of the condenser, and the set pressure required by the pressure detecting means. In a state in which is not detected, provided that the temperature detection means has detected a temperature higher than the saturation temperature at the set pressure of the pressure detection means,
And a control means for stopping the operation of the compressor.

In order to preferably achieve the above-mentioned intended purpose, a refrigerating apparatus according to another invention of the present application comprises a compressor for compressing a refrigerant and a supply of a high-pressure / high-temperature vaporized refrigerant compressed by the compressor. A water-cooled condenser that receives it, an expansion valve to which the liquefied refrigerant condensed by this condenser is supplied, an evaporator that receives the refrigerant that is expanded and vaporized through this expansion valve, and a constant condensation pressure of the condenser. In a refrigeration system equipped with a regulating valve that regulates the amount of cooling water supplied to the condenser in order to maintain the temperature of the condenser, pressure detection means for detecting a high pressure on the refrigerant discharge side of the compressor, and heat in the condenser. A temperature detection means for detecting the temperature of the replaced cooling water and a temperature higher than the saturation temperature at the set pressure of the pressure detection means in a state where the pressure detection means does not detect the required set pressure. The condition that Te, characterized by being composed of a control means for stopping the operation of the compressor.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a refrigerating apparatus according to the present invention will be described below with reference to the accompanying drawings with reference to preferred embodiments. (Regarding First Embodiment) FIG. 1 shows a first embodiment of a refrigerating apparatus according to the present invention, in which the refrigerating apparatus 10 includes a compressor 12 for compressing a refrigerant such as Freon, and the compressor 12. 12
Condenser 14 that receives the supply of the high-pressure / high-temperature vaporized refrigerant that has been compressed by, the expansion valve 16 that supplies the liquefied refrigerant that is condensed by this condenser 14, and the supply of the refrigerant that has expanded and vaporized through this expansion valve 16. And an evaporator 18 for receiving the water. Further, in the evaporator 18, heat exchange is performed with the vaporized refrigerant expanded through the expansion valve 16, and the vaporized refrigerant whose temperature has risen due to this heat exchange returns to the compressor 12 to generate high pressure /
After being compressed to a high temperature, it is subjected to recirculation. Note that reference numeral 20
Indicates a temperature-sensitive cylinder for detecting the refrigerant temperature on the refrigerant outlet side of the evaporator 18, and the expansion valve 16 is connected by the temperature-sensitive cylinder 20.
Aperture control is performed.

A high pressure switch 30 for detecting high pressure is inserted in the refrigerant discharge pipe 28 of the compressor 12.
The high-pressure switch 30 is set to operate when the high-pressure pressure from the compressor 12 becomes lower than the set pressure due to refrigerant leakage, and the detection signal is input to the control means 32. Further, the control means 32 stops the compressor 12 based on the input of the detection signal of the high-voltage switch 30 to prevent the compressor 12 from overheating due to the shortage of the refrigerant.

A cooling pipe (not shown) connected to the condenser 14 is configured to be supplied with cooling water from a supply source (not shown), and is condensed in a cooling water discharge pipe 22 communicating with the cooling pipe. A pressure control valve 24 is inserted. The adjusting valve 24 detects the high pressure of the refrigerant outlet pipe 26 of the condenser 14 and is controlled to open and close so as to keep the high pressure constant. That is, when the high pressure becomes higher than the preset pressure (set pressure), the amount of cooling water is increased, and when the high pressure becomes lower than the set pressure, the amount of cooling water is decreased to adjust the opening.

A temperature sensor 34 is provided on the refrigerant outlet pipe 26 of the condenser 14, and the temperature sensor 34 is connected to the control means 32. This temperature sensor 34 is
It is set to operate when a set temperature higher than the saturation temperature at the set pressure of the high pressure switch 30 is detected and to input the detection signal to the control means 32. The control means 32 is set to stop the operation of the compressor 12 when the detection signal from the temperature sensor 34 is received even when the high pressure switch 30 is not operated (FIG. 2). reference). That is, if the inside of the condenser 14 is saturated, the saturation temperature of the high pressure and the temperature of the refrigerant flowing out from the condenser 14 should be equal. Therefore, the refrigerant temperature being higher than the saturation temperature of the high pressure means that the superheated steam is 1
It means that it is flowing out from No. 4, and it can be surely judged that the refrigerant is insufficient. As a result, a slight refrigerant leak in which the high-pressure switch 30 does not operate can be detected by an increase in the temperature of the refrigerant flowing out of the condenser 14, and the compressor 12 can be stopped. Therefore, deterioration or seizure due to overheating of the compressor 12 can occur. It is possible to prevent the occurrence of failures such as.

An alarm means (not shown) such as a lamp or a bell is connected to the control means 32, and the high-voltage switch 30 is connected.
When the detection signal is input from the temperature sensor 34 while the set pressure is not detected, the operation of the compressor 12 is stopped and the alarm means is activated to cause a worker to leak a refrigerant (abnormality). ) Is recommended.

(Regarding the operation of the first embodiment) The above-mentioned first
In the refrigeration system 10 according to the embodiment, when the operation of the compressor 12 is started, the high-pressure / high-temperature vaporized refrigerant compressed by the compressor 12 is supplied to the condenser 14, where heat is generated between the refrigerant and the cooling water. After exchange, the vaporized refrigerant is liquefied. Condenser 14
The liquefied refrigerant condensed in (1) is supplied to the expansion valve 16, and the refrigerant expanded and vaporized through the expansion valve 16 is supplied to the evaporator 18, where heat is exchanged with external air, an ice making plate, etc. The vaporized refrigerant whose temperature has risen due to heat exchange returns to the compressor 12.

If the amount of refrigerant in the refrigeration system 10 is normal, the saturation temperature of the high pressure in the refrigerant discharge pipe 28 of the compressor 12 and the refrigerant temperature of the refrigerant outlet pipe 26 of the condenser 14 are the same. Has become. However, if the refrigerant leaks due to some cause and a refrigerant shortage occurs, the high pressure in the refrigerant discharge pipe 28 of the compressor 12 gradually decreases and the refrigerant temperature rises. Further, since the high pressure decreases in the condenser 14, the condensation pressure adjusting valve 24
Is reduced, the amount of cooling water is reduced, and the temperature of the refrigerant flowing through the refrigerant outlet pipe 26 is increased. When the temperature sensor 34 detects the set temperature while the high pressure switch 28 does not detect the set pressure, the operation of the compressor 12 is stopped via the control means 32. That is, since the compressor 12 can be stopped by detecting a slight refrigerant leak in which the high-pressure switch 30 does not operate, deterioration of the cooling capacity due to overheating of the compressor 12 and deterioration and deterioration such as seizure occur in advance. Can be prevented.

(Regarding the Second Embodiment) FIG. 3 shows a second embodiment of the refrigerating apparatus according to the present invention, the basic structure of which is the same as that of the first embodiment. The difference is that a temperature sensor 34 is provided in a pipe 36 between the evaporator 16 and the evaporator 18. Also in this embodiment, the temperature sensor 3
The set temperature of 4 is set to a temperature higher than the saturation temperature at the set pressure of the high pressure switch 30. Therefore, even if the high pressure switch 30 does not detect the set pressure,
When the temperature sensor 34 detects the set temperature, it is determined that a refrigerant leak has occurred, the operation of the compressor 12 is stopped, and the occurrence of a failure such as a reduction in cooling capacity or seizure can be prevented. .

(Regarding the third embodiment) FIG. 4 shows a third embodiment of the refrigerating apparatus according to the present invention, the basic structure of which is the same as that of the first embodiment, and the condenser 14 The difference is that a temperature sensor 35 is provided in the discharge pipe 22 of the cooling water for cooling. Also in this embodiment, the set temperature of the temperature sensor 35 is set to a temperature higher than the saturation temperature at the set pressure of the high pressure switch 30. That is, the temperature of the cooling water that has undergone heat exchange in the condenser 14 is
Since the temperature of the refrigerant flowing out from the condenser 14 is almost the same, when the temperature sensor 35 detects the set temperature while the high pressure switch 30 does not detect the set pressure, the compression is performed via the control means 32. If the machine 12 is stopped, it is possible to prevent a decrease in the cooling capacity and a failure of the compressor 12.

(Regarding Fourth Embodiment) FIG. 5 shows a fourth embodiment of the refrigerating apparatus according to the present invention, and the refrigerating apparatus 10 comprises an air-cooled condenser 14. That is,
A cooling fan 38 is disposed near the condenser 14, and the refrigerant discharge pipe 28 and the refrigerant outlet pipe 26 of the condenser 14 are provided.
Are connected by a branch pipe 40, and a condensation pressure adjusting valve 42 is inserted in the branch pipe 40. This condensing pressure adjusting valve 42
Is for maintaining the high pressure at a predetermined pressure or more, and if the amount of the refrigerant is appropriate, the refrigerant supplied from the compressor 12 is allowed to flow into the condenser 14 without flowing through the branch pipe 40, When the high pressure becomes low due to insufficient pressure, the refrigerant is set to flow directly from the branch pipe 40 to the refrigerant outlet pipe 26. Further, a temperature sensor 34 is provided in the refrigerant outlet pipe 26, and when the sensor 34 detects a set temperature higher than the saturation temperature at the set pressure of the high pressure sensor 30,
The operation of the compressor 12 is stopped via the control means 32. Reference numeral 44 represents a receiver tank in which the liquefied refrigerant condensed in the condenser 14 is temporarily stored.

In the fourth embodiment, when the high pressure of the refrigerant discharged from the compressor 12 decreases due to the leakage of the refrigerant, the condensing pressure adjusting valve 42 is controlled to be opened / closed and discharged from the compressor 12 as described above. Branch pipe 4
It will flow to the refrigerant outlet pipe 26 via 0. That is, since the refrigerant discharged from the compressor 12 flows through the refrigerant outlet pipe 26 at a high temperature without being dissipated in the condenser 14, the setting is made earlier than the high pressure switch 30 detects the set pressure. The temperature sensor 34 detects a set temperature higher than the saturation temperature at the pressure. As a result, the operation of the compressor 12 is stopped via the control means 32, and it is possible to prevent deterioration of the cooling capacity and failure of the compressor 12 in advance.

(Regarding Modifications) It is to be noted that the refrigerator is configured to circulate a high-temperature refrigerant (hot gas) by the defrosting operation of the evaporator and the ice making machine by the deicing operation. The completion of the deicing operation is detected by a temperature detection sensor such as a thermostat arranged in the evaporator. Therefore, it is possible to detect that the temperature of the refrigerant flowing out of the condenser reaches the set temperature by the temperature detection sensor.

[0022]

As described above, according to the refrigerating apparatus of the present invention, even if a slight refrigerant leak occurs, it can be detected with certainty to reduce the cooling capacity and reduce the compressor. It is possible to prevent the occurrence of the failure. That is,
It is possible to prevent a decrease in operating efficiency and an increase in running cost due to the time required for parts replacement and adjustment due to a failure of the compressor. Moreover, since the structure is extremely simple, the manufacturing cost can be kept low.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a refrigerating apparatus according to a first preferred embodiment of the present invention.

FIG. 2 is a chart diagram showing operation timings of main components of the refrigerating apparatus according to the first embodiment.

FIG. 3 is a schematic configuration diagram of a refrigerating apparatus according to a second preferred embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a refrigerating apparatus according to a preferred third embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a refrigerating apparatus according to a preferred fourth embodiment of the present invention.

[Explanation of symbols]

12 compressors, 14 condensers, 16 expansion valves, 18 evaporators, 2
4 Condensation pressure adjusting valve 26 Refrigerant outlet pipe, 30 High pressure switch, 32 Control means, 3
4 Temperature sensor 35 Temperature sensor, 42 Condensation pressure control valve

Claims (4)

[Claims] 1. A compressor (12) for compressing a refrigerant, a condenser (14) for receiving a high-pressure / high-temperature vaporized refrigerant compressed by the compressor (12), and a condenser (14). An expansion valve (16) to which the condensed liquefied refrigerant is supplied, an evaporator (18) receiving the expansion and vaporized refrigerant supplied through the expansion valve (16), and the condenser
In the refrigerating apparatus having a pressure adjusting valve (24, 42) for keeping the condensing pressure of (14) constant, a pressure detecting means (30) for detecting a high pressure on the refrigerant discharge side of the compressor (12), Temperature detecting means (34) for detecting the refrigerant temperature on the refrigerant outlet side of the condenser (14), and the temperature detecting means (34) in a state in which the pressure detecting means (30) does not detect the required set pressure. ) Is configured to include a control means (32) for stopping the operation of the compressor (12) on condition that a temperature higher than the saturation temperature at the set pressure of the pressure detection means (30) is detected. Refrigeration equipment. 2. The temperature detecting means (34) includes the condenser (1).
The refrigeration system according to claim 1, which is provided in the refrigerant outlet pipe (26) of 4). 3. The expansion valve (1) is provided with the temperature detecting means (34).
A conduit (36) between the (6) and the evaporator (18).
The refrigeration system described. 4. A compressor (12) for compressing a refrigerant, a water-cooled condenser (14) supplied with a high-pressure, high-temperature vaporized refrigerant compressed by the compressor (12), and this condenser ( An expansion valve (16) to which the liquefied refrigerant condensed in 14) is supplied, an evaporator (18) which is supplied with the refrigerant expanded and vaporized through this expansion valve (16), and the condensation of the condenser (14). The condenser (14) to keep the pressure constant
In a refrigerating apparatus having a regulating valve (24) for regulating the amount of cooling water supplied to, a pressure detecting means (30) for detecting a high pressure on the refrigerant discharge side of the compressor (12), and the condensing A temperature detection means (35) for detecting the temperature of the cooling water that has undergone heat exchange in the vessel (14), and the temperature detection means (35) in a state where the pressure detection means (30) does not detect the required set pressure. 35) is composed of a control means (32) for stopping the operation of the compressor (12) on condition that a temperature higher than the saturation temperature at the set pressure of the pressure detection means (30) is detected, Refrigerating device.