JPH10103819A - Refrigerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly and accurately detect leak of a refrigerant without needing labor by a method wherein a high pressure liquid pipe is constituted in a manner to effect given vibration according to the state of a liquid refrigerant and from relation data between a vibration detecting signal from a vibration detecting sensor and a leak amount and a vibration state, leak of a refrigerant is detected. SOLUTION: A piping 11 for 50Hz resonance and a piping 12 for 60Hz resonance are disposed in a high pressure liquid pipe 7 running from a liquid receiving tank 3 to an expansion valve 4, and vibration sensor 13 and 14 are arranged and connected to a leak detecting means 16 through a lead wire 15. Weight and a piping size are determined so that the corresponding piping 11 for 50 Hz resonance or the piping 12 for 60 Hz resonance are not resonated when the high pressure pipe 7 is previously filled with a liquid refrigerant at a design stage. The size of the piping is determined so that natural frequency changes and the corresponding piping 11 for 50 Hz resonance or the piping 12 for 60Hz resonance is resonated when a gas liquid mixture refrigerant flows through the high pressure liquid pipe 7 when the high pressure liquid pipe 7 is previously filled with a liquid refrigerant at a design stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system using chlorofluorocarbon as a refrigerant, and more particularly to a refrigeration system suitable for detecting refrigerant leakage.

[0002]

2. Description of the Related Art Conventionally, a so-called specific Freon gas containing chlorine such as R-11 and R-22 has been used as a refrigerant in a refrigeration cycle of a refrigeration system. This specific Freon gas causes ozone layer destruction. It became clear that specific CFC gas was regulated. For this reason, so-called new refrigerants have been studied in place of the specified Freon gas, but currently, for example, HFC32, HFC125, HFC13
4a and HFC143a. In addition, HFC32 / 134a, HFC32
/ 125, HFC32 / 125 / 134a, HFC12
Although 5 / 143a / 134a and the like are considered, each maker is in the process of studying.

[0003] When a mixed refrigerant is used, there is a danger of ignition due to refrigerant leakage, and the development of means for detecting refrigerant leakage has been desired.

[0004]

Conventionally, the state of leakage of a refrigerant such as specific Freon gas has been determined by looking at the refrigerant in the sight glass by a human, and it is difficult to make an accurate determination.
There was a problem that required human labor. In addition, when the transition to the use of mixed refrigerants, in the case of mixed refrigerants, the leak state differs depending on the type and mixing ratio of the refrigerant, making it more difficult for humans to determine the leak state, but from the viewpoint of safety measures, refrigerant leakage There is an urgent need for the development of accurate detection means.

Accordingly, an object of the present invention is to provide a refrigeration apparatus for detecting a refrigerant leak without requiring early and accurate manpower.

[0006]

According to a first aspect of the present invention, an evaporator, a compressor and a condenser are connected by a pipe, and a liquid receiving tank and an expansion valve disposed at an inlet of the evaporator are connected to a high-pressure liquid. In a refrigerating apparatus connected by a pipe to form a refrigerating cycle,
The high-pressure liquid pipe is configured to perform predetermined vibration according to the state of the liquid refrigerant filled in the pipe, a vibration detection sensor that detects predetermined vibration, a vibration detection signal from the vibration detection sensor, and a refrigerant determined in advance. And a leak detecting means for detecting a leak state of the refrigerant based on the relation data between the leak amount and the vibration state. According to this means, the high-pressure liquid pipe is configured to make a predetermined vibration according to the state of the liquid refrigerant, the predetermined vibration is detected by the vibration detection sensor, and the vibration detection signal and the leak amount obtained in advance are determined. The leakage of the refrigerant is detected from the data related to the vibration state. As a result, a leak can be detected during the operation of the refrigeration cycle without requiring accurate and early labor, and safety can be ensured, a decrease in refrigeration capacity can be prevented, and waste due to refrigerant discharge can be avoided in advance.

According to a second aspect of the present invention, the evaporator, the compressor and the condenser are connected by a pipe, and the liquid receiving tank and an expansion valve provided at the inlet of the evaporator are connected by a high-pressure liquid pipe. In a refrigerating apparatus forming a cycle, a resonance pipe that vibrates at a predetermined resonance when a leak amount of a refrigerant becomes a predetermined amount is provided so as to be bypassed to a high-pressure liquid pipe according to a frequency of 50 Hz or 60 Hz of a power source. A vibration detecting sensor for detecting vibration of a predetermined resonance, and a leak detecting means for detecting a leak state of the refrigerant based on a vibration detection signal from the vibration detecting sensor and data on a relationship between the amount of vibration of the refrigerant and the vibration state obtained in advance. Are provided. According to this means, a resonance pipe that resonates when the leak amount is a predetermined amount is provided in the high-pressure liquid pipe, and the vibration of the resonance pipe is detected by the vibration detection sensor. The leakage of the refrigerant is detected from the relationship data. As a result, since the resonance point can be grasped, the leak can be detected during the operation of the refrigeration cycle, without requiring precise and early manual operation, ensuring safety and preventing a decrease in the refrigeration capacity and releasing the refrigerant. Waste can be avoided in advance.

According to a third aspect of the present invention, the evaporator, the compressor and the condenser are connected by a pipe, and the liquid receiving tank and an expansion valve provided at the inlet of the evaporator are connected by a high-pressure liquid pipe. In the refrigerating apparatus that forms a cycle, the high-pressure liquid pipe is configured to make a predetermined pulsation according to the state of the liquid refrigerant flowing in the pipe, and a pulsation detection sensor that detects a predetermined pulsation, and pulsation by the pulsation detection sensor. Leak detecting means for detecting a refrigerant leak state based on a detection signal and data on a relationship between a refrigerant leak amount and a pulsation state obtained in advance is provided. According to this means, the high-pressure liquid pipe is configured to make a predetermined pulsation according to the state of the liquid refrigerant flowing through the high-pressure liquid pipe, the predetermined pulsation is detected by the pulsation detection sensor, and the pulsation detection signal and the pulsation detection signal are obtained in advance. A refrigerant leak is detected from data on the relationship between the amount of leak and the pulsation state. by this,
Regardless of the frequency of the power source, accurate and early labor is not required, leaks can be detected during the operation of the refrigeration cycle, safety is ensured, refrigeration capacity is prevented from decreasing, and waste due to refrigerant discharge is determined in advance. Can be avoided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a refrigerating apparatus showing a first embodiment of the present invention. The refrigerating apparatus comprises a compressor 1, a condenser 2, a liquid receiving tank 3, an expansion valve 4, and an evaporator 5. Are sequentially connected to form a refrigerant cycle. In this refrigerant cycle, low-temperature and low-pressure refrigerant gas is compressed by the compressor 1 to become high-temperature and high-pressure frozen gas and flows into the condenser 2 through the high-pressure gas pipe 6 (in the direction of the arrow in the figure). The refrigerant cooled by the cold water and condensed and liquefied is supplied to the liquid receiving tank 3.
To be stored. The stored liquid refrigerant is sent by the high-pressure liquid pipe 7, the pressure of the liquid refrigerant is reduced according to the degree of opening of the expansion valve 4, and flows out to the evaporator 5 through the low-pressure liquid pipe 9. Reference numeral 8 denotes a condensing unit.

In the evaporator 5, the liquid refrigerant evaporates and is sucked and circulated by the compressor 1 through the low-pressure gas pipe 10.

A high-pressure liquid pipe 7 extending from the liquid receiving tank 3 to the expansion valve 4 is provided with a 50 Hz resonance pipe 11 and a 60 Hz resonance pipe 12 which are partially branched and joined. A detection sensor 13 and a vibration detection sensor 14 are provided, and are connected to a leak detection unit 16 by a lead wire 15.

The vibration detection sensor 13 and the vibration detection sensor 14
May be either a contact type sensor contacting the 50 Hz resonance pipe 11 or a 60 Hz resonance pipe 12, or a non-contact non-contact type sensor. In the case of a non-contact type sensor, resonance occurs as shown in the conceptual diagram of FIG. When the amplitude of the pipes 11 and 12 increases and reaches a predetermined amplitude a, contact with the resonance pipes 11 and 12 is detected. That is, the opposed vibration detection sensor 13 or 15 is connected to the resonance pipes 11 and 12.
Detects whether or not contact has been made.

Here, when the high-pressure liquid pipe 7 is filled with the liquid refrigerant in the design stage in advance, the corresponding 50 Hz resonance pipe 11
Alternatively, the weight and the dimensions of the pipe are determined so that the 60-Hz resonance pipe 12 does not resonate, and the natural frequency changes when the gas-liquid mixed refrigerant flows through the high-pressure liquid pipe 7 due to flashing, and the corresponding 50-Hz resonance pipe changes. Piping 11 or 60Hz
The dimensions and the like of the pipe are determined so that the resonance pipe 12 resonates. Then, for example, when the amplitude a of the predetermined value or more of the 50 Hz resonance pipe 11 or the 60 Hz resonance pipe 12 is n times or more within the predetermined time t, it is determined in advance whether or not to determine that the refrigerant is leaked and stored. To keep. In addition, 5
0 Hz resonance pipe 11 or 60 Hz resonance pipe 12
Is operated by opening and closing a stop valve (not shown) according to the frequency of the power source.

In this configuration, during actual operation, when there is no refrigerant leakage, or when there is a refrigerant amount, the high-pressure liquid pipe 7 is filled with a liquid medium and the 50 Hz resonance pipe 11 or 6 is filled.
The 0 Hz resonance pipe 12 does not resonate. Therefore, the leak detecting means 16 does not detect the leak of the refrigerant by the signal from the vibration detection sensor 13 or the vibration detection sensor 14, and the operation of the refrigeration cycle is performed. On the other hand, when the refrigerant leaks from any of them and the refrigerant in the refrigeration cycle decreases by a predetermined amount, a flash is generated in the high-pressure liquid pipe 7 to become a gas-liquid mixed refrigerant, and the total weight of the refrigerant inside the high-pressure liquid pipe 7 decreases. As a result, the 50 Hz resonance pipe 11 or the 60 Hz resonance pipe 12 becomes close to a predetermined natural frequency, and the vibration width increases as in the example shown in FIG. Is output as a vibration detection signal.

In the leak detecting means 16, predetermined prescribed values L1 and L2 are set up and down as shown in FIG. 3, and when the number of times exceeding the prescribed value within a prescribed time t is a predetermined n or more, It outputs a leak detection signal S2 assuming that the refrigerant has leaked. When the compressor 1 starts, the leak detection means 16 does not operate because the high-pressure liquid pipe 7 is not filled with the refrigerant, and the detection request signal S1 is input so that the leak detection means 16 starts leak detection. I have to.

As described above, according to the first embodiment, when the refrigerant leaks by a predetermined amount or more, the leak of the refrigerant is detected by causing the resonance pipe provided in advance to resonate. It can be done without human intervention. As a result, it is possible to secure the safety by preventing the change of the characteristics of the mixed refrigerant in the refrigeration cycle, the occurrence of a fire, etc., the prevention of environmental destruction, the occurrence of an oxygen deficiency accident, etc. There is no waste of refrigerant discharge.

The 50 Hz resonance pipe 11 or 6
Although the 0 Hz resonance pipe 12 is provided, the high-pressure liquid pipe 7 itself may resonate. If the 50 Hz resonance pipe 11 or the 60 Hz resonance pipe 12 cannot be provided in the condensing unit 8, the pipe is provided outside. It may be mounted as a unit. In addition, a warning can be displayed on the display device by a leak detection signal from the leak detecting means 16 or the occurrence of a leak can be notified by voice.

FIG. 4 is a block diagram of a refrigeration apparatus showing a second embodiment of the present invention. The refrigeration apparatus has a pulsation detection sensor 17 mounted on the high-pressure liquid pipe 7 and a refrigerant according to the pulsation level. The other configuration is almost the same as that of the first embodiment shown in FIG.

As shown in FIG. 5, the pulsation detection sensor 17 is attached to the high-pressure liquid pipe 7 and detects the amplitude of the high-pressure liquid pipe 7 in time series. In the second embodiment, the pulsation level is small when the high-pressure liquid pipe 7 is filled with the liquid refrigerant and in a laminar flow state, and the pulsation level is large during the turbulent flow due to the leakage of the refrigerant due to the leakage of the refrigerant. Among them, the pulsation level generated as the refrigerant gas becomes larger is determined and measured, and the specified value is stored.

In this configuration, during actual operation, when there is no leakage of refrigerant or when the amount of Lee is less than a predetermined amount, the high-pressure liquid pipe 7 is filled with a liquid medium, the high-pressure liquid pipe 7 becomes laminar, and the pulsation level is increased. In such a case, the pulsation detection sensor 17
The pulsation level signal is not detected by the leak detecting means 16 as a leak, and the normal refrigeration cycle operation is performed. On the other hand, when the refrigerant leaks from any of them and the refrigerant in the refrigeration cycle decreases by a predetermined amount, a flash is generated in the high-pressure liquid pipe 7 and becomes a gas-liquid mixed refrigerant, and the turbulent flow is generated.
Flows to

As a result, in the leak detecting means 16,
For example, as shown in FIG. 6, it is detected that the pulsation level increases as the ratio of the liquid refrigerant in the refrigerant decreases. In such a case, the leak detecting means 16
When it is equal to or greater than a predetermined value, it is determined that the refrigerant leaks,
It outputs a leak detection signal S2.

As described above, according to the second embodiment, the leakage of the refrigerant can be detected from the pulsation level caused by the laminar flow state or the turbulent flow state in the high-pressure liquid pipe 7. Therefore, it is possible to cope with a frequency change of an inverter or the like, detect leaks accurately during operation quickly and without any need for manual operation, ensure safety, reduce refrigeration capacity, and reduce the cost of expensive refrigerants. No waste.

[0024]

As described above, according to the first aspect of the present invention, the high-pressure liquid pipe is configured to vibrate in a predetermined manner in accordance with the state of the liquid refrigerant. Since the leak of the refrigerant is detected from the data on the relationship between the amount and the vibration state, it does not require human labor accurately at an early stage.
Leakage can be detected even during operation, and safety can be ensured, refrigeration capacity can be prevented from lowering, and waste of refrigerant can be avoided in advance.

According to the second aspect of the present invention, the high-pressure liquid pipe is provided with a resonance pipe that resonates when the leak amount is a predetermined amount, and the high-pressure liquid pipe is provided with a resonance pipe based on the vibration detection signal and data obtained in advance on the relation between the leak amount and the resonance state. The refrigerant leak is detected by paying attention to the leak, so that the leak can be detected without any need for accurate manual operation at an early stage, and the safety can be ensured, the refrigeration capacity can be prevented from being reduced, and the refrigerant can be prevented from being wasted. .

According to the third aspect of the present invention, the high-pressure liquid pipe is constituted so as to make a predetermined pulsation in accordance with the state of the liquid refrigerant flowing through the high-pressure liquid pipe. Detects refrigerant leaks from the relationship data and ensures accurate and early detection of leaks regardless of the frequency of the power source, ensuring safety and preventing loss of refrigeration capacity. And waste of the refrigerant can be avoided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration apparatus showing a first embodiment of the present invention.

FIG. 2 is an operation diagram of a vibration sensor provided in the refrigeration apparatus of FIG.

FIG. 3 is an operation diagram of a leak detection unit provided in the refrigeration apparatus of FIG. 1;

FIG. 4 is a configuration diagram of a refrigeration apparatus showing a second embodiment of the present invention.

5 is an operation diagram of a vibration sensor provided in the refrigeration apparatus of FIG.

FIG. 6 is an operation diagram of a leak detection unit provided in the refrigeration apparatus of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Liquid receiving tank 4 Expansion valve 5 Evaporator 6 High pressure gas pipe 7 High pressure liquid pipe 8 Condensing unit 9 Low pressure liquid pipe 10 Low pressure gas pipe 11 50 Hz resonance pipe 12 60 Hz resonance pipe 13, 14 Vibration Detection sensor 15 Lead wire 16 Leak detection means 17 Pulsation detection sensor

Claims (3)

[Claims] 1. A refrigeration system in which an evaporator, a compressor, and a condenser are connected by a pipe, and a liquid receiving tank and an expansion valve provided at an inlet of the evaporator are connected by a high-pressure liquid pipe to form a refrigeration cycle. In the apparatus, the high-pressure liquid pipe is configured to perform predetermined vibration in accordance with a state of a liquid refrigerant filled in the pipe, and a vibration detection sensor that detects the predetermined vibration; and a vibration detection signal by the vibration detection sensor. A refrigerating apparatus comprising: a leak detecting unit configured to detect a leak state of the refrigerant based on data obtained beforehand and a relationship between the amount of the refrigerant leak and the vibration state. 2. A refrigeration system in which an evaporator, a compressor, and a condenser are connected by piping, and a liquid receiving tank and an expansion valve provided at an inlet of the evaporator are connected by a high-pressure liquid pipe to form a refrigeration cycle. In the apparatus, a resonance pipe that vibrates at a predetermined resonance when a leakage amount of the refrigerant becomes a predetermined amount is provided so as to bypass the high-pressure liquid pipe according to a frequency of 50 Hz or 60 Hz of a power source, and the predetermined resonance is provided. A vibration detection sensor that detects vibration of the refrigerant, and a leak detection unit that detects a refrigerant leak state based on a vibration detection signal from the vibration detection sensor and data on a relationship between a leakage amount of the refrigerant and a vibration state obtained in advance. A refrigeration apparatus characterized by the above-mentioned. 3. A refrigeration system in which an evaporator, a compressor, and a condenser are connected by piping, and a liquid receiving tank and an expansion valve provided at an inlet of the evaporator are connected by a high-pressure liquid pipe to form a refrigeration cycle. In the device, the high-pressure liquid pipe is configured to make a predetermined pulsation according to a state of the liquid refrigerant flowing in the pipe, a pulsation detection sensor that detects the predetermined pulsation, and a pulsation detection signal by the pulsation detection sensor. A refrigeration apparatus comprising: a leak detection unit configured to detect a refrigerant leak state based on relation data between a refrigerant leak amount and a pulsation state obtained in advance.