JP2001255046A - Refrigeration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect generating state of flash gas in detail with high accuracy. SOLUTION: A refrigerant pipe between a condenser and a pressure reducing unit is provided with a sight glass 7 having an inspection hole for confirming the state of refrigerant flowing through the pipe, a light emitting section 7E provided in the sight glass 7 and emitting light to traverse the refrigerant flowing through the pipe, A light receiving section 7F for receiving light from the light emitting section 7E and outputting a light receiving signal, and means for making a decision whether the quantity of refrigerant is deficient or not based on at least two values of the intensity of the light receiving signal, variation width, inclination of variation and the number of times of oscillation. Since generating state of flash gas can be detected in detail, the decision can be made with high accuracy whether the quantity of refrigerant is deficient or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system which detects whether or not a flash gas is mixed in a refrigerant flowing in a refrigerant pipe and can determine whether or not the amount of the refrigerant is insufficient.

[0002]

2. Description of the Related Art Generally, a refrigerating apparatus is formed by a compressor for compressing a refrigerant, a condenser for condensing the refrigerant, a decompression device for decompressing or narrowing the refrigerant, an evaporator for evaporating the refrigerant, and the like. The refrigerant is connected and the refrigerant is sealed in the refrigerant tube.

[0003] At this time, if there is a leakage point such as a pinhole at a connection point of the refrigerant pipe or the like for some reason, the refrigerant gradually leaks therefrom, and the amount of the refrigerant becomes insufficient.

In a state where the amount of the refrigerant is insufficient, the refrigeration efficiency is reduced, so that it is necessary to replenish the refrigerant and to repair a leaked portion. Therefore, it is necessary to check whether the amount of the refrigerant is insufficient.

The most direct method of checking the refrigerant amount is to check the pressure in the pipe, but this requires an operation such as connecting a pressure gauge to the refrigerant pipe, and is troublesome. During operation, there is a possibility that refrigerant leakage or the like may occur.

When the amount of the refrigerant becomes insufficient, bubbles called flash gas are mixed in the liquid refrigerant. Therefore, it is determined whether or not the amount of the refrigerant is insufficient by detecting the bubbles. Can be considered.

From such a viewpoint, for example, Japanese Patent Application Laid-Open No. 7-4
No. 3052, JP-A-8-145518, etc., a light emitting element and a light receiving element are provided on both sides of a pair (two) of sight glasses, and light from the light emitting element is received by a light receiving element (photo sensor). ) Discloses a refrigeration device that receives light.

Then, it is detected whether or not the flash gas is generated based on a change in the amount of received light due to scattering of the light from the light receiving element by the flash gas, and based on the detection result, whether or not the refrigerant amount is insufficient. I am to judge.

[0009]

However, in the above configuration, whether or not the flash gas is generated is detected only by a change in the amount of light received by the light receiving section, and based on this, it is determined whether or not the refrigerant amount is insufficient. Therefore, there is a problem in that the amount of the refrigerant is erroneously determined to be insufficient due to the flash gas generated in a transient state when the refrigeration apparatus is started.

Further, even when the refrigerant reaches a steady state, it may be difficult to accurately determine that dust or the like is mixed in the refrigerant.

[0011] That is, although it is ideal that the refrigerant does not originally contain dust and the like, dust is generated from the sliding portion of the motor constituting the compressor due to long-term operation, and the dust is generated at the site. May stick to glass or scatter light.

In such a case, since the amount of light received by the light receiving element is reduced, it is erroneously determined whether or not flash gas is generated, that is, whether or not the amount of refrigerant is insufficient.

[0013] Further, even when dust temporarily passes through and causes scattering, a change in the amount of light may occur, and this may be erroneously detected as the generation of flash gas.

Further, if the generation of the flash gas is performed only by the change in the amount of light received by the light receiving element, it is difficult to obtain the details of the generation state, and therefore, the alarm for notifying the shortage of the refrigerant must be uniform. There was no problem.

Accordingly, an object of the present invention is to provide a refrigeration apparatus capable of detecting the flash gas generation state in detail and with high accuracy, and performing detailed notification based on the detection. And

[0016]

In order to solve the above problems, the invention according to claim 1 is directed to a refrigeration cycle in which a compressor, a condenser, a decompression device, and an evaporator are connected in a ring by a refrigerant pipe. In the refrigeration apparatus in which is formed, a sight glass provided in a refrigerant pipe through which a liquid refrigerant flows, and provided with an observation window for visually confirming a state of the refrigerant flowing in the pipe, and a sight glass provided in the sight glass A light-emitting unit that emits light so as to traverse the refrigerant flowing in the refrigerant tube, a light-receiving unit that receives light from the light-emitting unit and outputs a light-receiving signal, the intensity of the light-receiving signal, a variation width, Determining means for determining whether or not the refrigerant amount is insufficient based on at least two values of the change gradient and the number of vibrations, so that the generation state of the flash gas can be detected in detail, Whether there is a shortage Characterized in that so as to increase the determination accuracy.

According to a second aspect of the present invention, a flash gas is provided by providing a reflecting plate for reflecting light emitted from a light emitting unit on a sight glass, and receiving light reflected by the reflecting plate at a light receiving unit. In which the occurrence state of the refrigerant is detected in detail so as to enhance the accuracy of determining whether or not the refrigerant amount is insufficient.

According to a third aspect of the present invention, when the determination means determines that the amount of the refrigerant is insufficient, a control means including a notification device for notifying by light or sound is provided to provide a detailed alarm. Can be notified.

According to a fourth aspect of the present invention, there is provided a stopping means for judging whether or not the refrigeration system has reached a steady operation, and stopping the judgment by the judging means when it is judged that the steady operation has not been reached. Thus, erroneous determination in determining whether the refrigerant amount is insufficient is prevented.

According to a sixth aspect of the present invention, it is determined whether the refrigeration system has reached a steady operation based on the elapsed time from the start of the operation of the refrigeration system. Erroneous judgment in the judgment of (1) is prevented.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a refrigerating apparatus, and the refrigerating apparatus 1 is used for a refrigerator or an air conditioner.

2 is a compressor, 3 is a condenser provided with a blower 50, 4 is a receiver tank, 5 and 11 are service valves,
6 is a filter dryer, 7 is a moisture indicator (corresponding to a sight glass), 8 is a solenoid valve (open / close valve), 9
Is an expansion valve (decompression device), 10 is an evaporator, 12 is an accumulator with a built-in strainer, 13 is a check valve, 14 is an accumulator, and these are connected in a ring by a refrigerant pipe.
HC (hydrocarbon) refrigerant and the like are circulated.

Reference numeral 15 denotes a refrigerant pipe connecting the refrigerant pipe on the outlet side of the receiver tank 4 and the compressor 2. The refrigerant pipe 15 is provided with a strainer 16 and a capillary tube 17.

A refrigerant tube 19 connects the inlet side of the receiver tank 4 and the inlet side of the accumulator 12. The refrigerant tube 19 is provided with a capillary tube 20, a high / low pressure switch 21, and a capillary tube 22.

FIGS. 2 and 3 show the moisture indicator 7, 7A is a glass viewing window, 7B is a moisture detector,
7C is a reflector, and 7D is a sensor.

The sensor 7D includes a light emitting section 7E for emitting infrared rays and a light receiving section 7F for receiving infrared rays.

As shown in FIG. 2, flash gas (bubble)
If 23 is present in the liquid refrigerant, this flash gas 23
Infrared rays are scattered in the light receiving portion 7F, and the amount of light received by the light receiving portion 7F changes.

A control device 24 shown in FIG.
(Control means) that receives a light receiving signal from the sensor and a signal from another sensor to control the compressor 2, the expansion valve 9, the notification device 25, and the like, and that the refrigeration device 1 is in a transient state. In this case, the state of the refrigerant is temporarily stopped (stop means).

The notification device 25 may be any one of methods such as a flashing lamp, a notification sound such as a buzzer or an alarm sound, a display indicating "refrigerant leakage" on a display, or a method of indicating refrigerant leakage by a light or a symbol. This is done by one or more.

Next, the operation of the control device 24 will be described with reference to FIG. First, it is determined whether the operation of the refrigeration apparatus 1 is in a transitional state. This is determined by whether or not a predetermined time has elapsed from the start of operation (S
1).

The determination of the elapse of the predetermined time is based on the following reasons. That is, in a transitional state from the start of the operation to the steady operation, a sufficient amount of the liquid refrigerant may not be flowing through the refrigerant pipe, and the liquid refrigerant containing the flash gas (bubbles) may be flowing. .

In such a state, when the control device 24 operates to detect the flash gas, it is determined that the refrigerant is insufficient, resulting in a malfunction. Therefore, in the transient state, the control device 2
4 is not performed to determine the shortage of the refrigerant.

Since the transition time varies depending on the size, capacity and the like of the refrigeration system 1, in the present invention, the transition time is determined in advance by the set time of the timer. This makes it possible to easily cope with the case where the transition times are different.

After the predetermined time has elapsed, it is next determined whether or not the increase in load is equal to or more than a predetermined value (S2).

If the increase in load is equal to or greater than a predetermined value,
It is determined that the state is a transitional state, and the light receiving signal from the sensor 7D is not input, or the light receiving signal from the sensor 7D is ignored.

When a predetermined time has elapsed from the start of operation and the rise in load does not exceed the predetermined value, a light receiving signal from the sensor 7D is input (S3).

If the refrigerant circulating in the moisture indicator 7 is in a liquid state, infrared rays from the light emitting section 7E are reflected by the reflector 7C and received by the light receiving section 7F.

In this state, no notification is made because the refrigerant is not leaking or because the amount of leaking refrigerant is small even if it is leaking.

When the leakage of the refrigerant increases, the flash gas comes to be mixed with the refrigerant circulating in the moisture indicator 7, and the infrared rays from the light emitting section 7E are scattered by the flash gas.

FIG. 6 shows a case where flash gas is not generated (FIG. 6A) and a case where flash gas is generated (FIG. 6A).
FIG. 6B is a diagram illustrating the state in the refrigerant pipe in (b)) and the light receiving signal from the light receiving unit 7F at that time.

As can be seen from the figure, when no flash gas is generated, the infrared rays from the light emitting section 7E are reflected by the reflecting plate 7C without being scattered and received by the light receiving section 7F. Therefore, the light receiving signal output from the light receiving section 7F does not change with time.

However, when the flash gas is generated, the amount of light received by the light receiving portion 7F changes, and the light receiving signal changes accordingly.
As a result, the amount of infrared light received by the light receiving section 7F is significantly reduced.

Therefore, generation of flash gas is determined from the change in the light receiving signal. As the determination factors, the signal intensity I of the received light signal, the change width D of the received light signal, the slope G of the received light signal, the number of vibrations N of the received light signal, and the like can be listed.

When flash gas is generated, the signal intensity I
Becomes smaller, it can be determined that flash gas has been generated when the signal intensity I becomes smaller than a preset threshold value Vth.

However, such a decrease in the signal strength I is as follows.
This also occurs when dust or the like is mixed in the refrigerant, and the threshold Vth
It is difficult to accurately judge the generation of flash gas only by using the gas.

However, in the case of dust, the signal intensity I is temporarily reduced only when the dust passes, or the dust vibrates depending on the density of the dust.

On the other hand, when flash gas is generated due to lack of refrigerant, the signal intensity I decreases steadily and oscillates at a substantially constant frequency.

Therefore, in the present invention, at least two values of the signal intensity I from the light receiving section 7F, the change width D of the signal intensity, the gradient G of the change in the signal intensity, and the number of oscillations N of the signal intensity are determined by the judging means. Then, it is determined whether or not the refrigerant is insufficient.

In general, when the change of the received light signal due to the flash gas and the dust is compared, the change width D of the signal intensity I and the gradient G of the change are larger in the dust.

In the case of dust, the change in the signal intensity I is often one-shot (in a case where it recovers in a short time). In contrast, in the case of the flash gas, it does not recover after a signal change. Vibrates constantly.

Therefore, depending on whether the signal intensity I is smaller than the threshold value Vth and the variation width D or the gradient G of the variation is equal to or greater than a predetermined value, whether the change in the signal intensity I is due to dust or flash gas is determined. Can be determined.

It is also possible to distinguish whether the change in signal strength is due to dust or flash gas depending on whether the change is sporadic and whether the changed signal strength I is constantly oscillating. Will be able to

When it is determined that the amount of the refrigerant is insufficient, the control device 24 activates the notifying device 25 (not shown) to notify the user of the refrigerant leakage.

At this time, for example, the generation state of the flash gas, that is, the shortage state of the refrigerant amount can be determined from the magnitude of the change width of the signal intensity. It is possible to configure so that when a maintenance check or the like is required, the case where the maintenance check is urgently required is notified separately.

When the notification device 25 is activated and notified, the user responds to the refrigerant leakage by calling a service person.

As described above, the refrigeration system 1 of the present invention automatically determines whether or not a refrigerant leaks and notifies the refrigeration system. Therefore, the labor of a service person and a manager of the operation of the refrigeration system 1 can be reduced as much as possible. In addition to this, it is possible to promptly respond to the leakage of the refrigerant.

In particular, when a flammable HC refrigerant is used, there is a possibility that the leaked refrigerant may burn (or explode if the amount of leakage is large), and it is desirable to take prompt measures. Can respond.

Further, according to the present invention, it is relatively easy to dispose a reflecting plate 7C on the inner wall of the moisture indicator 7, and the sensor 7D having the light emitting unit 7E and the light receiving unit 7F is also provided from the outside of the viewing window. Since it can be installed, the installation itself is relatively easy, and it can be applied relatively easily to the refrigeration apparatus 1 already installed.

Further, since it is determined whether or not the operation of the refrigeration apparatus 1 is in a transitional state by determining whether or not the operation of the refrigeration apparatus 1 is within a predetermined period of time from the start of the operation of the refrigeration apparatus 1, the transitional state is determined. Although the time varies depending on the size of the refrigeration apparatus 1 and the difference in the amount of refrigerant charged (the difference in the total length of the refrigerant pipe), it can be relatively easily handled only by setting the timer time, and the cost increase can be suppressed.

The above-mentioned transient state refers to a state from the start of operation to a steady operation, or a state in which the load suddenly increases or decreases and the operation follows the load. .

[0061]

As described above, according to the first aspect of the present invention, the viewing port is provided on the refrigerant pipe through which the liquid refrigerant flows, and is used to visually check the state of the refrigerant flowing through the pipe. A sight glass, provided on the sight glass,
A light-emitting unit that emits light so as to traverse the refrigerant flowing in the refrigerant tube, a light-receiving unit that receives light from the light-emitting unit and outputs a light-receiving signal, and the intensity, change width, and change of the light-received signal Determining means for determining whether the refrigerant amount is insufficient based on at least two values of the inclination and the number of vibrations, so that the generation state of the flash gas can be detected in detail, The accuracy of determining whether the refrigerant amount is insufficient can be improved.

According to the second aspect of the present invention, since the sight glass is provided with the reflecting plate for reflecting the light emitted from the light emitting unit, the light reflected by the reflecting plate is received by the light receiving unit. In addition, the generation state of the flash gas can be detected in detail, and the accuracy of determining whether the refrigerant amount is insufficient can be improved.

According to the third aspect of the present invention, when the judging means judges that the amount of the refrigerant is insufficient, the control means provided with the notifying device for notifying by the light or the sound is provided. It will be possible to issue detailed warnings.

According to the fourth aspect of the present invention, it is determined whether or not the refrigeration system has reached the steady operation, and if it is determined that the refrigeration system has not reached the steady operation, the stopping means for stopping the determination by the determining means. Is provided, it is possible to prevent erroneous determination in determining whether the refrigerant amount is insufficient.

According to the invention of claim 6, it is determined whether or not the refrigeration system has reached a steady operation based on the elapsed time from the start of the operation of the refrigeration system. It is possible to prevent an erroneous determination in determining whether or not to make a determination.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a refrigeration apparatus applied to an embodiment of the present invention.

FIG. 2 is a plan view of a moisture indicator (sight glass) of the refrigeration apparatus.

Fig. 3 Moisture indicator (sight glass)
FIG. 5 is a diagram showing a relationship between the detector and the detector.

FIG. 4 is a block diagram showing each device of the refrigeration apparatus.

FIG. 5 is a flowchart showing a control operation of the refrigeration apparatus.

FIG. 6 is a diagram illustrating a state of a liquid refrigerant flowing in a refrigerant pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration apparatus 2 Compressor 3 Condenser 7 Moisture indicator (sight glass) 7A Viewing window 7C Reflector 7E Light emitting part 7F Light receiving part 9 Decompression device 10 Evaporator 24 Control device (control means, stop means) 25 Notification device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Ikumin Taniguchi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. No. 5-5 Sanyo Electric Co., Ltd. (72) Inventor Akira Oiwa 2-5-5 Sanyo Electric Co., Ltd., Moriguchi-shi, Osaka (72) Inventor Yoshio Ida Keihanhondori, Moriguchi-shi, Osaka 2-5-5 Sanyo Electric Co., Ltd. F-term (reference) 3L060 AA01 AA02 CC19 DD01 DD06 EE01 3L061 BC07 BD03

Claims (5)

[Claims] 1. A refrigeration system in which a compressor, a condenser, a decompression device, and an evaporator are annularly connected by a refrigerant tube to form a refrigeration cycle. And a sight glass provided with a viewing window for visually confirming the state of the refrigerant flowing in the pipe, and light is provided to the sight glass and emitted so as to cross the refrigerant flowing in the pipe of the refrigerant pipe. A light-emitting unit, a light-receiving unit that receives light from the light-emitting unit and outputs a light-receiving signal, and a refrigerant based on at least two or more values of the intensity, change width, change gradient, and number of vibrations of the light-received signal. A refrigerating apparatus comprising: a judging means for judging whether or not the amount is insufficient. 2. The sight glass is provided with a reflector for reflecting light emitted from a light emitting unit, and the light reflected by the reflector is received by the light receiving unit. The refrigeration apparatus according to 1. 3. The control device according to claim 1, further comprising a control device including a notifying device for notifying by light or sound when the refrigerant amount is determined to be insufficient. 3. The refrigeration apparatus according to 2. 4. A stopping means for judging whether or not the refrigeration apparatus has reached a steady state operation and stopping the judgment by the judging means when it is judged that the steady state operation has not been reached. The refrigeration apparatus according to any one of claims 1 to 3, wherein 5. The refrigeration apparatus according to claim 4, wherein whether or not the refrigeration apparatus has reached a steady state operation is determined based on an elapsed time from the start of the operation of the refrigeration apparatus.