JP2008064453A - Coolant leakage detecting method and refrigerating cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coolant leakage detecting method and a refrigerating cycle device facilitating attachment of a sensor, and capable of carrying out accurate coolant leakage detection in regard to a refrigerating cycle device. <P>SOLUTION: A step is provided for calculating a coolant amount in a liquid pool from a coolant liquid level position in the liquid pool of a refrigerating cycle circulating a coolant by connecting a compressor, a condenser, the liquid pool, an expanding means, and an evaporator by a piping. A step is provided for judging if there is coolant leakage by comparing a coolant amount associated with a condensation temperature and an evaporation temperature of the refrigerating cycle during normal operation, and the newly calculated coolant amount. A step is provided for discriminating whether it is within a certain time after compressor activation when calculating the coolant amount in the liquid pool. If it is discriminated that the certain time has passed after the compressor activation, the coolant amount is calculated by the coolant liquid level position to judge if there is coolant leakage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus for a refrigerator mainly used as a cooling source for a showcase or the like, and more particularly to detection of refrigerant leakage.

In FIG. 12, which is a conventional refrigeration cycle apparatus, 101 is a compressor, 102 is a condenser, 103 is a liquid receiving tank (liquid reservoir), 104 is an expansion valve, 105 is an evaporator, 106 is a high pressure gas pipe, and 107 is a high pressure. The liquid pipe, 108 is a solenoid valve, 109 is a low pressure liquid pipe, 110 is a low pressure gas pipe, 111 is a low pressure switch, 112 is an auxiliary tank, 112a is the lower part of the auxiliary tank 112 and the liquid receiving tank (liquid reservoir) 103. A communication pipe that communicates the lower part, 112b is a communication pipe that communicates the upper part of the auxiliary tank 112 and the upper part of the liquid receiving tank (liquid reservoir) 103, and 113 is a float type level sensor (see, for example, Patent Document 1).

In the above configuration, the compressor 101, the condenser 102, the liquid receiving tank 103, the expansion valve 104, and the evaporator 105 are sequentially connected to form a refrigerant cycle, and the liquid receiving tank 103 and the auxiliary tank 112 are connected to each other. By communicating with the communication pipes 112a and 112b, the liquid refrigerant in the liquid receiving tank 103 and the auxiliary tank 112 is brought to the same liquid level. The auxiliary tank 112 is provided with a float level sensor 113 so that the liquid level can be detected. Whether the detected liquid level of the liquid receiving tank 103 is equal to or higher than a predetermined normal liquid level. The refrigerant leak is detected. The refrigerant flow and action in the refrigeration cycle are well known and will not be described.

In FIG. 13, which is another conventional refrigeration cycle apparatus, 202 is a compressor, 203 is a condenser, 204 is a receiver tank (liquid reservoir), 205 is a control valve, 206 is a refrigeration showcase, 207 is an evaporator, and 208 is A liquid take-out tube, 209 is a flow sight (sight glass), 210 is a dryer, 211 is an accumulator, 212 is a light emitter, 213 is a light receiver, and 214 is a discrimination circuit (see, for example, Patent Document 2).

In the above configuration, the compressor 202, the condenser 203, the receiver tank 204, the control valve 205, and the evaporator 207 are sequentially connected to form a refrigerant cycle, and the liquid take-out pipe 208 extending from the lower part of the receiver tank 204 is connected to the dryer. A flow site (sight glass) 209 is attached via 210, and the outflow state of the refrigerant liquid from the receiver tank 204 is confirmed. That is, light is emitted from the light emitter 212 toward the refrigerant liquid flowing in the flow site 209, received by the light receiver 213, and determined by the determination circuit 214 based on the level of the detection signal of the light receiver 213. Detecting air bubbles in the tank, that is, refrigerant leakage. Note that the refrigerant flow and action of the refrigeration cycle are well known as described above, and thus the description thereof is omitted.

JP-A-10-103820 JP-A-6-185839

  As described above, the conventional refrigeration cycle apparatus shown in FIG. 12 measures the liquid level in the liquid reservoir 103 to detect the leakage of the refrigerant, the liquid reservoir 103 or the liquid reservoir 103 and the communication pipes 112a and 112b. It is necessary to make a hole in the connected auxiliary tank 112 and to attach a liquid level measuring means such as the float type level sensor 113, and it takes a lot of labor to install the liquid level measuring means. In addition, since the refrigerator is basically operated for 24 hours, the liquid level measuring means cannot be attached to the liquid reservoir of the refrigerator that has already been installed and operated, and the measured refrigerant liquid level in the liquid reservoir. Even if the height is the same, the refrigerant amount (refrigerant weight) will be different if the refrigerant temperature is different. If the measured refrigerant liquid level in the liquid reservoir is not converted to weight using temperature, there is a risk of misjudgment of refrigerant leakage. There was a problem that there was.

  In a normal operation with no refrigerant leakage, the amount of refrigerant in the liquid reservoir 103 (the weight of the refrigerant) depends on the saturation temperature of the refrigerant in the condenser 102 or the pressure on the high pressure side of the compressor 101, or in the evaporator 105. Changes occur according to changes in the saturation temperature of the refrigerant or the pressure on the low pressure side of the compressor 101, and the manner of this change has a certain relationship determined by the system configuration. However, there is a problem that accurate refrigerant leak detection, that is, early detection of refrigerant leak cannot be performed.

Further, in the conventional refrigeration cycle apparatus of FIG. 13, bubble detection means such as the light emitter 212, the light receiver 213, and the discrimination circuit 214 are attached to the sight glass 209 on the outlet side of the liquid reservoir 204, so that the refrigerant liquid is supplied. Although the refrigerant leak is detected by detecting the mixing of bubbles, the refrigerant leak cannot be detected unless there is almost no refrigerant liquid in the liquid reservoir and the refrigerant liquid level is lowered to the position of the outlet pipe of the liquid reservoir. Since the refrigerant leak cannot be detected at an early stage and the detection means detects the refrigerant leak, it takes a short time until the phenomenon that the refrigerator cannot maintain the predetermined performance due to the lack of the refrigerant. There was a problem that it was not possible to take measures to refill the refrigerator with refrigerant before it became warm and deteriorated in freshness.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a refrigerant leak detection method and a refrigeration cycle apparatus that can accurately detect a refrigerant leak.

  The refrigerant leakage detection method for a refrigeration cycle apparatus according to the present invention includes a compressor, a condenser, a liquid reservoir, an expansion means, and an evaporator connected by piping to circulate the refrigerant in the liquid reservoir of the refrigeration cycle. Calculating the amount of refrigerant in the liquid reservoir from the position, and comparing the amount of refrigerant related to the condensation temperature and evaporation temperature of the refrigeration cycle during normal operation with the newly calculated amount of refrigerant to determine refrigerant leakage And determining whether the refrigerant amount in the liquid reservoir is within a certain period of time after starting the compressor when calculating the amount of refrigerant in the liquid reservoir, The refrigerant amount is calculated to determine refrigerant leakage.

The refrigerant leakage detection method according to the present invention comprises a step of determining whether a certain time has elapsed after starting the compressor when calculating the amount of the refrigerant in the liquid reservoir. Since the refrigerant amount is calculated from the refrigerant liquid level position and the refrigerant leak is judged, the refrigerant leak can be detected with high accuracy.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a refrigeration cycle apparatus showing an example of an embodiment of the present invention.
In the figure, 1 is a compressor, 2 is a condenser, 3 is a condenser blower, 4 is a liquid reservoir, 5 is a solenoid valve, 6 is expansion means, 7 is an evaporator, 8 is an evaporator blower, and 9 is a high-pressure gas pipe. 10 is a low-pressure gas pipe, 11 is a high-pressure liquid pipe on the inlet side of the liquid reservoir 4, 12 is a high-pressure liquid pipe on the outlet side of the liquid reservoir 4, 13 is a refrigerant leak detecting means, 15 is a liquid level measuring means, 30 is, for example, It is a temperature measuring means such as a thermistor, and measures, for example, the surface temperature of the liquid reservoir 4.
For example, one or a plurality of the compressor 1, the electromagnetic valve 5, the expansion means 6, the evaporator 7, and the evaporator blower 8 are installed. The condenser 2 and the condenser blower 3 are installed, for example, in a machine room or outdoors, and the evaporator 7 and the evaporator blower 8 are built in, for example, a showcase installed in a store or the like.

FIG. 2 is a view showing the liquid reservoir 4 of the refrigeration cycle apparatus configured as described above. In FIG. 2, the same or corresponding parts as those in FIG.
In the figure, reference numeral 14 denotes a casing made of, for example, a carbon steel pipe for pressure piping of the liquid reservoir 4, 15a denotes, for example, an ultrasonic sensor provided in the casing 14, and 15b denotes a controller of the ultrasonic sensor 15a. The liquid level measuring means 15 is constituted by these 15a and 15b. Reference numeral 16 denotes a refrigerant liquid level. FIG. 3 shows a Mollier diagram showing the operation of the refrigerant of the refrigeration cycle apparatus, and the reference numerals in the drawing correspond to the reference numerals in the configuration diagram of FIG.

First, the operation of the refrigeration cycle will be described. The low-temperature and low-pressure gas refrigerant is compressed by the compressor 1 to become a high-temperature and high-pressure gas refrigerant, and flows into the condenser 2 through the high-pressure gas pipe 9. The condenser 2 heats the surrounding fluid such as air and water. It exchanges heat and becomes a high-temperature and high-pressure liquid refrigerant, and flows into the liquid reservoir 4 through the high-pressure liquid pipe 11 connected to the liquid reservoir inlet at the top of the liquid reservoir 4. The high-temperature and high-pressure liquid refrigerant that has flowed into the liquid reservoir 4 flows out of the high-pressure liquid pipe 12 connected to the liquid reservoir outlet at the bottom of the liquid reservoir 4, passes through the electromagnetic valve 5, and then is decompressed by the expansion means 6 to be low temperature. The refrigerant becomes a low-pressure two-phase refrigerant and flows into the evaporator 7. In the evaporator 7, heat exchange with the surrounding fluid, for example, air, becomes a low-temperature and low-pressure gas refrigerant, and enters the compressor 1 via the low-pressure gas pipe 10. Inhaled.

Next, the amount of refrigerant in the refrigeration cycle will be described. For example, in a refrigerator used for cooling for a supermarket showcase, the showcase is installed in the food department, but the number, size, type, and arrangement differ depending on the store where it is installed, and are arranged in the showcase accordingly. The internal volume of the evaporator 7 is also different. Moreover, the installation location of the compressor 1, the condenser 2, and the liquid reservoir 4 also differs depending on the store structure. For example, the compressor 1, the condenser 2, and the liquid reservoir 4 may be installed behind the food department or on the roof. The distances between the machine 1, the condenser 2, and the liquid reservoir 4 are changed, and the lengths of the low-pressure gas pipe 10 and the high-pressure liquid pipe 12 are also different.

In order for the refrigeration cycle to exhibit the specified performance, an amount of refrigerant suitable for the internal volume of the refrigeration cycle is required, and the amount of refrigerant required for the entire refrigeration cycle differs depending on the internal volume of the evaporator and the length of the piping. Therefore, the refrigerant of the refrigerator is charged after configuring the refrigeration cycle at the site where the equipment is installed. In addition, the amount of refrigerant required in the refrigeration cycle varies depending on the state of the refrigeration cycle, and the state of the refrigeration cycle varies depending on the outside air temperature and the operating state of load-side equipment such as showcases. Regardless of the state, a little more refrigerant is charged so that the necessary amount of refrigerant is always distributed to each component device such as a condenser and an evaporator.

Therefore, the refrigerant | coolant amount allocated to the compressor 1, the condenser 2, the evaporator 7, and the piping 9-12 is decided by each internal volume, performance, and an operating state, and, among the refrigerant | coolants with which the refrigerating cycle was filled, a refrigerating cycle. The surplus refrigerant after each component device reaches the appropriate amount of refrigerant will be accumulated in the liquid reservoir 4. Therefore, the amount of refrigerant in the liquid reservoir 4 changes from moment to moment depending on the state of the refrigeration cycle, but by measuring the refrigerant pressure, saturation temperature, etc. in each component such as the condenser 2 and the evaporator 7, The refrigerant amount in the liquid reservoir 4 can be estimated by subtracting the refrigerant amount from the refrigerant charge amount. That is, the amount of refrigerant in the liquid reservoir 4 is measured by measuring the amount of refrigerant in the liquid reservoir 4 at a certain time and comparing it with the operating state of the normal refrigeration cycle or the amount of refrigerant in the liquid reservoir 4 at the previous time. It is possible to know the refrigerant leakage from the refrigeration cycle by calculating and judging in the refrigerant leakage detection means 13 whether or not is within the normal change range.

However, since the liquid reservoir 4 stores high-pressure liquid refrigerant inside, the liquid reservoir 4 is formed of a metal such as a carbon steel pipe for pressure piping, and is not a pressure vessel designed and manufactured in consideration of pressure resistance in accordance with regulations. However, it is possible to provide a transparent portion such as a viewing window in a part thereof, but in practice, most of the liquid reservoir 4 is an opaque container. Note that the term “opaque” means optically opaque, and it is impossible to measure the internal liquid level from the outside of the liquid reservoir 4 using something similar to light or to see through the entire interior of the liquid reservoir 4 by visual observation. It means that. Even if an optically transparent viewing window is attached to a part of the liquid reservoir 4, the liquid level in the liquid reservoir 4 is constantly changing. It is difficult to measure or monitor the exact position of the.

On the other hand, high-frequency vibrations such as sound waves or ultrasonic waves have the property of being transmitted in any medium such as gas, liquid, and solid. By utilizing this property, the liquid reservoir 4 is provided from the outside of the casing 14 of the liquid reservoir 4. The measurement of the liquid level of the refrigerant liquid in 4 can be considered. The ultrasonic wave is transmitted through any medium having elasticity, and is used for any of gas, liquid, and solid. The speed at which ultrasonic waves propagate through the medium depends on the type of medium and the temperature.

  Table 1 shows the sound speed of typical media. In the table, the value in () represents the temperature of the medium, and the unit is [cm / s].

The sound speeds of air, water, and metal in the table are the values described in the “Science Chronology” published by Maruzen on November 30, 1995, and the sound speed of Freon was released from NIST in 1998. The value calculated using the software “REFPROP Ver6.01” is shown. Also, R22 and R404A in the table are chlorofluorocarbon refrigerants, and R404A is a mixed refrigerant in which a plurality of refrigerants are mixed. The table shows the values at the standard composition. Further, since the refrigerant gas exists in the upper part and the refrigerant liquid exists in the lower part in the liquid reservoir, the sound speeds of both when the refrigerant is liquid and when it is gas are shown in the table.

There are several methods for generating ultrasonic waves. Examples of such methods are shown below.
First, a method using a magnetostrictive vibrator. Metals such as nickel and iron-aluminum alloys, and nickel-copper-cobalt ferrite expand or contract when a magnetic field is applied. Due to this property, ultrasonic vibration occurs when a high-frequency current is passed through a winding for creating a magnetic field.

Next, a method using an electrostrictive vibrator. When a DC electrode is applied to a sintered body such as a barium titanate porcelain or a lead zirconate titanate porcelain and a DC electric field is applied, it is deformed. Due to this property, when a high frequency electric field is applied between the electrodes, ultrasonic vibration is generated.

Next, a method using a piezoelectric vibrator. Piezoelectric crystals such as quartz, Rochelle salt, and piezoelectric ceramic expand or contract or slide when an electric field is applied. When this property is utilized and a high frequency voltage is applied, ultrasonic vibration is generated.

Several examples of ultrasonic generation methods have been described above, but any of these methods may be used, or other methods for generating ultrasonic waves may be used.

If there is a different medium while the ultrasonic wave travels, part of it is reflected and part of it is transmitted. When ultrasonic waves are perpendicularly incident on the medium 2 having the density ρ1 and the velocity c1 from the medium 1 having the density ρ2 and the velocity c2, the reflectance R and the transmittance T of the ultrasonic waves are expressed by the following equations.
R = (ρ2 × c2−ρ1 × c1) / (ρ1 × c1 + ρ2 × c2)
T = 1-R

Also, the time τ during which an ultrasonic wave travels in a medium can be obtained from the propagation velocity c and propagation distance L in the medium by the following equation.
τ = L / c
Therefore, the ultrasonic transmitter and receiver are integrated as an ultrasonic sensor, the ultrasonic sensor transmitter transmits ultrasonic waves, and the ultrasonic waves reflected and returned at the interface of the medium are received by the receiver. If the time Δt from transmission to reception is measured, the thickness L of the medium can be obtained from the following equation.
L = (Δt × c) / 2

It is assumed that, for example, an ultrasonic sensor 15a in which a transmitter and a receiver are integrated is installed at the bottom of the casing 14 of the liquid reservoir 4. The ultrasonic wave transmitted from the transmitter of the ultrasonic sensor 15 a is incident from the outer surface of the housing 14, travels through the inside at a speed corresponding to the material, and reaches the inner surface of the housing 14. Then, since there is a refrigerant liquid in the casing 14, reflection occurs at the interface between the casing 14 and the refrigerant liquid, and a part of the ultrasonic wave is again transmitted through the casing 14 and is received by the receiver of the ultrasonic sensor 15a. Received, the rest passes through the interface. Note that the reflectance and transmittance of the ultrasonic wave at this time can be obtained from the above-described equations.

Further, the ultrasonic wave transmitted through the interface between the casing 14 and the refrigerant liquid is transmitted through the refrigerant liquid at a speed corresponding to the physical properties and temperature of the refrigerant liquid, and reaches the refrigerant liquid surface 16 that is the interface between the refrigerant liquid and the refrigerant gas. To do. Then, a part of the ultrasonic wave is reflected by the refrigerant liquid surface 16 at the interface, is transmitted again through the refrigerant liquid, further passes through the housing 14 and is received by the receiver of the ultrasonic sensor.

However, some of the ultrasonic waves reflected by the refrigerant liquid surface 16 at the interface and transmitted through the refrigerant liquid are reflected by the interface between the refrigerant liquid and the casing 14 when entering the casing 14 of the liquid reservoir 4. Some reflections reach the receiver several times, and the ultrasonic wave that has passed through the coolant liquid level 16 is also reflected by the casing 14 on the upper surface of the liquid reservoir 4, and this is also reflected several times. Some of them repeatedly reach the receiver, which is a very complicated phenomenon. Therefore, it is necessary to discriminate which ultrasonic wave is reflected at which interface by calculation.

FIG. 4 shows a configuration diagram of the ultrasonic sensor 15 a, the ultrasonic controller 15 b, and the refrigerant leak detection unit 13 of the liquid level measurement unit 15.
The ultrasonic sensor 15a of the liquid level measuring means 15 includes a transmitter 23 and a receiver 24, and the ultrasonic controller 15b includes an ultrasonic generation circuit 25, a storage device 26 such as a memory, a timer 27, a calculation device 28, For example, it comprises an output device 29 such as a liquid crystal display or a D / A converter. On the other hand, the refrigerant leak detection means 13 is configured by an input device 40 such as an A / D converter, an arithmetic device 41, an output device 42 such as a liquid crystal display or a D / A converter, and a storage device 43 such as a memory. The

Next, the operation will be described. The ultrasonic generator circuit 25 of the ultrasonic controller 15b moves the transmitter 23 of the ultrasonic sensor 15a to generate ultrasonic waves. Then, as described above, the ultrasonic wave reflected at the interface of the medium is received by the receiver 24 and sent to the arithmetic unit 28. On the other hand, as shown in Table 1, for example, as shown in Table 1, the ultrasonic propagation speed and thickness for each temperature, or the temperatures of the refrigerant liquid and the refrigerant gas, which are stored in advance in the storage device 26, are shown. Information on the ultrasonic wave propagation speed for each time and information on the time of the timer 27 are also sent to the arithmetic unit 28. Based on these pieces of information, the arithmetic unit 28 reflects the ultrasonic wave reflected and returned at the interface between the casing 14 of the liquid reservoir 4 and the refrigerant liquid, and returns after reflecting at the interface between the refrigerant liquid and the refrigerant gas. The ultrasonic waves or the ultrasonic waves that have returned after being repeatedly reflected at each interface are separated by calculation. Then, the height of the refrigerant liquid surface 16 is obtained from the time from transmission to reception of the ultrasonic wave reflected and returned at the interface between the refrigerant liquid and the refrigerant gas, and this is output from the output device 29.

Then, the refrigerant liquid level information of the liquid reservoir 4 output from the output device 29 of the liquid level measuring means 15 is input to the input device 40 of the refrigerant leak detecting means 13 and stored in the storage device 43 in advance. On the basis of an algorithm described later, calculation is performed in the calculation device 41, the presence or absence of refrigerant leakage and the amount of refrigerant leakage are determined, and the output device 42 displays a display device (not shown) such as a user monitoring device or a display. Is output. Further, the current and past refrigerant liquid level, condensing temperature, evaporating temperature, the presence or absence of refrigerant leakage, and the amount of refrigerant leakage are newly stored in the storage device 43.

In the measurement by the ultrasonic sensor 15a, it is assumed that the ultrasonic sensor 15a and the casing 14 of the liquid reservoir 4 are in close contact with each other and there is almost no other substance between them. That is, the mounting portion of the ultrasonic sensor 15a is made of a soft material so that air does not enter between the casing 14 and the ultrasonic sensor 15a, and pressure is applied to the ultrasonic sensor 15a to the casing 14. It is desirable to make it closely contact, and when this contact degree is weak, detection accuracy will deteriorate. As the material of the attachment portion of the ultrasonic sensor 15a, for example, rubber or a gel-like substance can be considered, and as a method of applying pressure to the ultrasonic sensor 15a, for example, a method using a magnetic force of a magnet or a belt tension is used. The method to use etc. can be considered.

Further, when the liquid level measuring means 15 is an ultrasonic sensor, it is less likely to be attached to the bottom of the liquid reservoir 4 and less susceptible to the effects of solar radiation and illumination, so that the reliability and measurement accuracy are improved. Desirable above. For example, when attached to the ceiling surface of the liquid reservoir 4, the ultrasonic wave will be transmitted in the order of the housing 14, refrigerant gas, refrigerant liquid, the transmission order will be different from when it is attached to the bottom surface, This can be handled by changing the calculation in the controller 15b. Therefore, the attachment position may be any position as long as the ultrasonic wave is incident substantially perpendicularly to the coolant level 16 of the liquid reservoir 4.

As described above, in principle, without providing a sensor inside the casing 14 of the liquid reservoir 4, the liquid level measuring means 15 such as the ultrasonic sensor 15a is installed outside the casing 14, The height of the coolant level 16 inside the liquid reservoir 4 can be measured.
However, this is a case where the fluid in the liquid reservoir 4 is stationary. Actually, as shown in FIG. 1, since the liquid reservoir 4 is disposed in the refrigeration cycle, there is always a refrigerant inside. The refrigerant liquid level 16 in the liquid reservoir 4 is constantly oscillating with a width of several millimeters. Therefore, in such a case, some measure is required to measure the refrigerant liquid level 16 by the liquid level measuring means 15 attached to the outside of the liquid reservoir 4.

As shown in FIG. 2 above, there is a high-pressure liquid pipe 11 on the liquid reservoir inlet side at the top of the liquid reservoir 4, and the liquid refrigerant flowing from the high-pressure liquid pipe 11 falls down as it is due to gravity and inertial force. It is considered that the refrigerant liquid level 16 collides with the refrigerant liquid level 16 and the refrigerant liquid level 16 in the liquid reservoir 4 is swung by the collision energy. The collision energy between the liquid refrigerant and the refrigerant liquid level 16 depends on the distance between the high pressure liquid pipe 11 and the refrigerant liquid level 16 and the amount of refrigerant circulating in the refrigeration cycle. The distance varies depending on the height of the coolant liquid level 16. It is considered that if the collision energy is different, the rocking width of the refrigerant liquid surface 16 is also different. In fact, it is confirmed by experiments that the rocking width of the refrigerant liquid surface 16 changes depending on the height of the refrigerant liquid surface 16. ing.

According to experiments, this oscillation width is about ± 4 mm when large, about ± 1 mm when small, and the oscillation frequency is about 1 Hz when small and about 3 Hz when large. Further, the fluctuation of the refrigerant liquid level 16 is caused by the generation of a vortex flow in the refrigerant liquid in the liquid reservoir 4, but it is considered that the vortex is not an unsteady phenomenon and cannot be made constant. Are known. The fluctuation of the refrigerant liquid level 16 does not cause the same fluctuation on the plus side and the minus side like a clean sine waveform. In addition, the fluctuation toward the minus side (lower side) is slower than the plus side (upper side), and the average position of the refrigerant liquid level 16 is simply the height between the plus side and the minus side. It seems a little below the average.

Therefore, the measurement of the refrigerant liquid level 16 of the liquid reservoir 4 by the liquid level measuring means 15 must be performed in consideration of the phenomenon specific to the liquid reservoir 4. Otherwise, an error will occur in the calculation and judgment in the refrigerant leak detection means 13, and it will be judged that the refrigerant has leaked even though the refrigerant has not leaked, or the refrigerant leak has occurred. There is a possibility that it will be determined that the problem has not occurred.

As a measuring and processing method, first, when the sampling frequency of the liquid level measuring means 15 coincides with the liquid level fluctuation frequency, the measured data always measures the same position of the liquid level that is fluctuating. This will need to be avoided.
As a method, a method of sampling and averaging at two different frequencies, such as 3 Hz and 5 Hz, or a method of reducing errors by measuring as long as possible at one sampling frequency, for example, 1 Hz for several minutes, etc. It is done.

In addition, the number of data samplings and the processing method must be determined in consideration of the rocking width and rocking frequency of the refrigerant liquid surface. For example, the sampling number is at least 10, preferably several tens or more, and the processing method is, for example, a method of determining an average so that it is about 20% lower than the simple average of measurement data. Further, since the refrigerant liquid level 16 greatly fluctuates when the compressor 1 starts and stops, the operation of the compressor 1 is linked with the measurement and data processing, and after a certain period of time, for example, 20 minutes after the compressor 1 moves. Performing measurements later is a method for reducing errors.

As described above, the height of the coolant level 16 in the liquid reservoir 4 can be measured. However, if the refrigerant leak is determined by directly using the height of the refrigerant liquid level 16 in the liquid reservoir 4, the estimation error is large and there is a risk of erroneous determination. The amount of refrigerant in the inside is calculated, and based on that. Therefore, in order to determine refrigerant leakage, it is necessary to calculate the refrigerant amount in the liquid reservoir 4 at a certain time and compare it with the operating state of the normal refrigeration cycle or the refrigerant amount in the liquid reservoir 4 at the previous time. . Since the refrigerant has different densities at different temperatures, in order to calculate the amount of refrigerant in the liquid reservoir 4 (the weight of the refrigerant), the height of the refrigerant liquid level 16 is measured by the liquid level measuring means 15, The temperature is measured by the temperature measuring means 30 (condensation temperature of the refrigerant by the surface temperature of the liquid reservoir 4 in FIG. 1), the density of the refrigerant liquid is obtained from the temperature, and the height of the refrigerant liquid surface 16 is converted into the refrigerant amount. calculate.

Next, FIG. 5 and FIG. 6 are diagrams showing a configuration example of another refrigeration cycle apparatus in the present embodiment. 5 and 6, the same or corresponding parts as those in the configuration diagram of FIG.
In the configuration example of FIG. 1 described above, the refrigerant leakage is determined based on two pieces of information of the refrigerant amount in the liquid reservoir 4 and the refrigerant condensation temperature based on the surface temperature of the liquid reservoir 4. In the configuration of FIG. 6, the accuracy of the refrigerant is further improved by determining the refrigerant leakage based on the three information of the refrigerant amount in the liquid reservoir 4, the condensation temperature, and the evaporation temperature. .
In FIG. 5, 30 a is a temperature measuring means such as a thermistor provided in the high-pressure liquid pipe 11, for example, and 30 b is a temperature sensor such as a thermistor provided in the low-pressure side channel extending from the expansion means 6 to the evaporator 7. The temperature measuring means measures the condensation temperature and the evaporation temperature by the temperature measuring means 30a and 30b, respectively.
In FIG. 6, reference numeral 31 a denotes a pressure measuring means such as a pressure sensor provided in the high-pressure gas pipe 9 on the discharge side leading to the compressor 1 and the condenser 2, and 31 b reaches the evaporator 7 and the compressor 1. Pressure measuring means such as a pressure sensor provided in the low pressure gas pipe 10 on the low pressure side, and the pressure detected by the pressure measuring means 31a on the high pressure side and the pressure measuring means 31b on the low pressure side is used as refrigerant leakage detection means. In 13, the condensation temperature and the evaporation temperature are obtained by converting into the saturation temperature.

FIG. 7 shows the relationship between the condensation temperature, that is, the saturation temperature of the refrigerant in the condenser 2, the evaporation temperature, that is, the saturation temperature of the refrigerant in the evaporator 7, and the amount of refrigerant in the liquid reservoir 4 (the weight of the refrigerant). FIG. In the figure, the evaporation temperature is shown for the case where the high-pressure liquid pipe 12 is long and short.

As shown in FIG. 7, the amount of refrigerant in the liquid reservoir 4 decreases as the condensation temperature increases, and decreases as the evaporation temperature increases. That is, as the condensation temperature increases, the temperature difference between the refrigerant in the condenser 2 and the ambient air increases, and the amount of heat exchange between the refrigerant and air, that is, the ability to condense the gas refrigerant into a liquid refrigerant increases. The proportion of the liquid refrigerant in the vessel 2 increases, and the amount of refrigerant in the entire condenser 2 increases accordingly, so that the excess refrigerant is reduced and the amount of refrigerant in the liquid reservoir 4 is reduced.

On the other hand, when the evaporation temperature increases, the temperature difference between the refrigerant in the evaporator 7 and the ambient air decreases, and the amount of heat exchange between the refrigerant and air, that is, the ability to evaporate the liquid refrigerant into a gas refrigerant decreases. The proportion of the liquid refrigerant in the evaporator 7 increases, and the amount of refrigerant in the entire evaporator 7 increases accordingly, so that the excess refrigerant decreases and the amount of refrigerant in the liquid reservoir 4 decreases.
Further, when the evaporation temperature increases, the density of the gas refrigerant sucked into the compressor 1 also increases, so that the refrigerant flow rate circulating in the refrigeration cycle increases, and the amount of refrigerant in the condenser 2 and the evaporator 7 increases accordingly. As a result, the excess refrigerant in the liquid reservoir 4 is reduced. When the evaporation temperature increases due to these two factors, the amount of refrigerant in the liquid reservoir 4 decreases.

Further, as shown in FIG. 7, when the high-pressure liquid pipe 12 becomes longer, the inclination of the change in the refrigerant amount in the liquid reservoir 4 with respect to the change in the condensation temperature becomes smaller. That is, as described above, the amount of refrigerant in the condenser 2 increases as the condensation temperature increases, but the density of the liquid refrigerant in the high-pressure liquid pipe 12 decreases, so that the amount of refrigerant in the high-pressure liquid pipe 12 increases as the condensation temperature increases. On the contrary decreases. Therefore, when the high-pressure liquid pipe 12 becomes longer, the ratio of the refrigerant amount in the high-pressure liquid pipe 12 to the refrigerant quantity in the entire refrigeration cycle increases, and the amount of refrigerant in the condenser 2 due to the change in the refrigerant amount in the high-pressure liquid pipe 12. Therefore, the amount of change in the refrigerant amount in the liquid reservoir 4 with respect to the change in the condensation temperature is reduced. The relationship of changes shown in FIG. 7 is confirmed by experiments and simulations.
The refrigerant quantity in the liquid reservoir 4 of the refrigerator, the condensing temperature, the evaporating temperature, and the high-pressure liquid pipe length have the above relationship, and the judgment of the refrigerant leakage must be made in consideration of this relationship.

FIG. 8 is a flowchart showing an example of the refrigerant leakage judgment algorithm, and Table 2 stores data on the refrigerant amount in the liquid reservoir 4 calculated based on the measured coolant liquid level and condensing temperature of the liquid reservoir 4. It is the table | surface which showed an example of the method of the division of a data area when memorize | storing in the memory of an apparatus. In Table 2, CT represents the condensation temperature, and ET represents the evaporation temperature.
Now, a case where the number of operating compressors 1 is the same as in the configuration examples of FIGS. 5 and 6 and the condensation temperature and the evaporation temperature are substantially the same is referred to as the same operating condition. As is clear from FIG. 7 described above, the amount of refrigerant in the liquid reservoir 4 is uniquely determined when the condensation temperature and the evaporation temperature are determined, so the amount of refrigerant in the liquid reservoir 4 under the same operating conditions is substantially the same. If there is a refrigerant leak, there will be a difference with the refrigerant amount data in the liquid reservoir 4 in the normal operation state. Therefore, if the refrigerant amount data in the normal operation state is learned and stored, The refrigerant leakage can be determined based on the above. Hereinafter, the refrigerant leakage judgment will be described based on an example of the method of dividing the data area in the flowchart of FIG.

  First, it is determined whether or not it is a data measurement time (for example, every hour) at Step 1, and if Yes, at Step 2, the condensation temperature, the evaporation temperature, and the height of the refrigerant liquid level 16 in the liquid reservoir 4 are measured. Note that the measurement of the height of the refrigerant liquid level 16 and the like is as described above, and a description thereof will be omitted here. In Step 3, it is determined whether or not the data in Step 2 is valid data. In other words, since the state of the refrigeration cycle will not be stable until a certain time has passed since the compressor moved, the elapsed time since the start of the compressor or the change in the number of operating compressors was counted and measured Data for which a certain time (for example, 20 minutes) has elapsed since the start of the compressor is determined as valid data, and data for which a certain time has not elapsed since the start is determined as invalid data.

If the determination in Step 3 is yes or not, the refrigerant in the liquid reservoir 4 is calculated based on the coolant level, the condensing temperature, etc. of the liquid reservoir 4 of the effective data measured in Step 4 next. The data area in which the quantity data is to be stored is determined by the areas divided into (1) to (16) as shown in Table 2 from the condensation temperature and the evaporation temperature.

In the data area, a data group learned and stored up to the previous measurement time is stored. The data group means an average value of a plurality of refrigerant amount data, the number of refrigerant amount data, a maximum value of deviation from the average value, and the like.

Next, in Step 5, it is determined whether or not the corresponding data area of the new refrigerant amount data determined in Step 4 is an effective area. In the determination of the effective area, a data area in which the number of the data groups learned and stored in the corresponding data area by the previous measurement time is a predetermined number or more (for example, 5 or more) is defined as an effective area. Name and judge.

If the corresponding data area is not an effective area in Step 5 (No), it is determined in Step 6 whether the refrigerant amount data calculated from the newly measured effective data is normal data. The normal data refers to data that is not so far from the average value of the plurality of refrigerant amount data stored in the corresponding data area. When noise is added to the measurement data, or when the temperature data is erroneously measured, the calculated refrigerant amount data greatly deviates from the average value, so that it is judged and abnormal data is excluded. In the case of normal data in Step 6 (Yes), the calculated refrigerant amount data is stored in the corresponding data area in Step 7, and the number of data in the corresponding data area is counted up by 1 in Step 8.

If the corresponding data area in Step 5 is an effective area (Yes), in Step 9, the refrigerant amount data calculated from the newly measured effective data is compared with the data in the corresponding effective area. Determine refrigerant leakage.
As a method for determining refrigerant leakage, for example, when the refrigerant amount data calculated from newly measured effective data is smaller than the data stored in the corresponding effective area, that is, in the liquid reservoir 4. There is a method of determining that a refrigerant leak has occurred when the amount of the refrigerant is decreasing and has continued for a certain period of time. The determination of the decreasing tendency will be described below.

For example, the data region has a range as shown in Table 2, and the data region (1) has a condensation temperature (CT) between 25 ° C. and 34 ° C. and an evaporation temperature (ET) between −25 ° C. and −21 ° C. The condensing temperature and the evaporating temperature have a range of 9 ° C. and 4 ° C., respectively, so that data between them is stored. Therefore, even if the average value of a plurality of refrigerant amount data stored in one data area and the refrigerant amount data calculated from the newly measured effective data are simply compared, the refrigerant amount in the liquid reservoir 4 is not increased. It is difficult to judge whether or not it is decreasing.
Therefore, based on a data group such as an average value of a plurality of refrigerant amount data stored in the corresponding data area, the number of refrigerant amount data, and the maximum value of deviation from the average value of each of the plurality of refrigerant amount data, When the deviation between the refrigerant amount data calculated from the newly measured effective data and the stored average value is larger than the maximum deviation from the average value, the refrigerant amount in the liquid reservoir 4 tends to decrease. It is determined that

And, for example, when the apparatus has failed or when maintenance is performed, when the refrigerant leak determination flow is not performed, as an end condition, for example, using a switch or the like, the operation of the switch is used as an end trigger, In Step 10, it is determined whether or not to end. If No, the refrigerant leakage determination flow is repeatedly executed, and if Yes, the process ends.

  As described above, in the first embodiment, since the sensor for judging the refrigerant leakage of the refrigerator is attached to the outside of the liquid reservoir, the installation work is easy, and it has already been installed and operated. It can be easily installed in the liquid reservoir of the refrigerator. Further, the height of the refrigerant liquid level in the liquid reservoir is measured by a sensor attached to the outside of the liquid reservoir, the refrigerant condensing temperature is measured by the temperature measuring means, and the density of the refrigerant liquid is obtained from the temperature. Since the liquid level is calculated by converting into the refrigerant amount (refrigerant weight) and the refrigerant leakage is judged from the change in the refrigerant amount, it can be detected accurately and early.

In the above embodiment, the liquid level measuring means 15 is attached to the outside of the liquid reservoir 4 to measure the refrigerant liquid level. However, for example, the liquid reservoir as shown in FIG. In the case of a refrigeration cycle apparatus configured with a tank connected thereto, the measurement is not limited to the liquid reservoir 4, and liquid level measuring means 15 may be provided outside the auxiliary tank for measurement.

The condensing temperature in the above embodiment is the condensing temperature by measuring the surface temperature of the liquid reservoir 4 or the refrigerant temperature of the high-pressure liquid pipe 11 connecting the condenser 2 and the liquid reservoir 4 or the compressor 1 and the condenser. 2 is not limited to the condensation temperature obtained by converting the refrigerant pressure to the saturation temperature by the pressure sensor provided in the high-pressure gas pipe 9 on the discharge side leading to 2, for example, the surface temperature of the auxiliary tank or the liquid reservoir 4, the refrigerant temperature in the auxiliary tank or the saturation temperature of the refrigerant in the condenser 2, or the condensation temperature by the refrigerant temperature measurement of the high-pressure liquid pipe 12 connecting the liquid reservoir 4 and the expansion means 6, or the compressor 1. The condensation temperature may be determined by converting the refrigerant pressure into a saturation temperature from the pressure measurement of the refrigerant by a pressure sensor provided at any position in the flow path from the discharge side to the expansion means 6.

Further, the evaporation temperature is determined by measuring the refrigerant temperature in the flow path from the expansion means 6 to the evaporator 7 or the pressure sensor provided in the low-pressure gas pipe 10 on the low-pressure side leading to the evaporator 7 and the compressor 1. It is not limited to the evaporating temperature obtained by converting the pressure measurement into the saturation temperature, for example, the saturation temperature measurement of the refrigerant in the evaporator 7 or any position in the flow path from the expansion means 6 to the compressor 1 The evaporation temperature may be determined by converting the refrigerant pressure to a saturation temperature based on the pressure measurement of the refrigerant using the pressure sensor.

In addition, it is better to judge the leakage of the refrigerant by using the three information of the amount of refrigerant in the liquid reservoir, the condensation temperature, and the evaporation temperature. For example, when the internal volume of the evaporator 7 is small, the evaporation temperature Since the effect of the change on the amount of refrigerant in the liquid reservoir 4 is smaller than the effect of the condensation temperature on the amount of refrigerant in the liquid reservoir 4, two amounts of refrigerant in the liquid reservoir and the condensation temperature as shown in FIG. You may make it judge refrigerant | coolant leakage with information.

Further, the refrigerant leakage determination algorithm is not limited to this example. For example, a straight line as shown in FIG. 7 is created from measured temperature data or calculated refrigerant amount data, and the straight line is generated. It may be determined that the refrigerant leaks when the data is far from, or the straight line of FIG. 7 is created as a standard pattern in advance by simulation or the like, and it is determined that the refrigerant leaks when it is far away from this. It may be.

Further, in the above embodiment, the liquid level measuring means 15 and the refrigerant leak detecting means 13 are separately provided, and the refrigerant leak detecting means 13 judges the refrigerant leak based on the measured value of the liquid level measuring means 15. However, the refrigerant leakage detection means 13 may be incorporated in the liquid level measurement means 15. For example, if the liquid level measuring means 15 is configured so that the refrigerant leak is determined in the arithmetic unit 28 in the liquid level measuring means 15, the refrigerant leak detecting means 13 may not be provided separately, and the configuration is simplified. Further, the refrigerant leak detection means 13 may be anything as long as it can add some calculation to the measurement information of the liquid level measurement means 15, and may be a personal computer, for example.

Embodiment 2. FIG.
In the present embodiment, the refrigeration cycle apparatus in the first embodiment is configured through a network.
9 and 10 are configuration diagrams of the refrigeration cycle apparatus in the present embodiment.
9 shows a case where only one refrigerator is arranged for one store, and FIG. 10 shows that a plurality of refrigerators (shown by two in the figure) are arranged for one store. Each case is shown. 9 and 10, the same or corresponding parts as those in the refrigeration cycle apparatus in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

9 and 10, 17 is a store of a supermarket or a convenience store, 18 is a showcase installed in the store 17, 19 is a refrigerator placed outside the store 17, and the showcase An evaporator (not shown) in 18 is connected by a high pressure liquid pipe 12 and a low pressure gas pipe 10. Reference numeral 20 denotes a network, which is a refrigerant leak detecting means for judging refrigerant leak based on measurement information of the liquid level measuring means 15 provided in close contact with the outside of the liquid reservoir 4 disposed in or near the refrigerator 19. 13 is connected via a wired line such as a telephone line or a wireless line such as a mobile line. 21 is connected to the network 20 by the wire or wireless, and is installed in a head office that manages the remote store or an office of a company that manages facilities, for example, a display means such as a CRT or a liquid crystal screen and a keyboard Remote monitoring means having input means such as a mouse and a button.

FIG. 11 shows a configuration diagram of the liquid level measuring means 15, the refrigerant leak detection means 13 and the remote monitoring means 21. In the figure, the same and corresponding parts as those of the liquid level measuring means 15 and the refrigerant leak detecting means 13 in the first embodiment are given the same reference numerals and their description is omitted.
The remote monitoring means 21 includes an input device 44 such as an A / D converter, an arithmetic device 45, an output device 46 such as a liquid crystal display or a D / A converter, and a storage device 47 such as a memory. The input device 44 of the remote monitoring means 21 and the output device 42 of the refrigerant leak detection means 13 are connected via the network 20 by wire or wireless.

In the present embodiment, the basic configuration operations such as the operation of the refrigeration cycle in the refrigeration cycle apparatus and the refrigerant leak determination of the liquid level measurement means 15 and the refrigerant leak detection means 13 are as described in the first embodiment. Therefore, the description here is omitted, and the point of using the network will be mainly described.

Information about the refrigerant liquid level in the liquid reservoir 4 measured by the liquid level measuring means 15 or the refrigerant leak calculated and judged by the refrigerant leak detecting means 13 is, for example, the headquarters operating the store 17 via the network 20 The data is sent to the remote monitoring means 21 installed in the office of a trader who manages the equipment.

The remote monitoring means 21 receives information such as the current and past refrigerant liquid level height, condensing temperature, evaporation temperature, presence or absence of refrigerant leakage, refrigerant leakage amount, etc. from the input device 44 via the network 20, and is stored in the storage device 47. The Since the computing device 45 of the remote monitoring means 21 can perform high-speed computation as compared with the computing device 41 of the refrigerant leak detection means 13, the computation of the refrigerant leak detection algorithm with a large computation amount is possible, and remote monitoring is possible. Since the storage device 47 of the means 21 has a larger capacity for storing data than the storage device 43 of the refrigerant leak detection means 13, it can store a large amount of data and can store data several hours ago or several days ago. Therefore, changes in refrigerant leakage can be analyzed retrospectively, and accurate judgment can be made.

  As described above, in the second embodiment, the refrigerant leakage detection means of a refrigerator installed in a store or the like, for example, the headquarters that manages the remote store, or the office of a trader who manages facilities, etc. By connecting the remote monitoring means via a network, such as a telephone line or wireless connection such as a mobile line, it is possible to monitor the occurrence of refrigerant leakage in the freezer at all times. You can discover and take action early.

  As described above, the refrigeration cycle apparatus of the present invention is a refrigeration cycle apparatus having a compressor, a condenser, a liquid reservoir, an expansion means, and an evaporator, or a refrigeration cycle apparatus having an auxiliary tank connected to the liquid reservoir. In addition, the liquid level measuring means for measuring the liquid level in the liquid reservoir or the auxiliary tank is provided, and it is attached to the outside of the liquid reservoir or the auxiliary tank for measurement. It can be easily mounted and measured in a liquid reservoir or auxiliary tank of a refrigerator already installed and operating. The surface temperature of the liquid reservoir or auxiliary tank, the refrigerant temperature in the liquid reservoir or auxiliary tank, the saturation temperature of the refrigerant in the condenser, or the condenser and the liquid reservoir or the liquid reservoir and the Temperature measuring means for measuring the refrigerant temperature of the pipe connecting the expansion means, or pressure measuring means for measuring the pressure of the refrigerant at any position in the flow path from the discharge side of the compressor to the expansion means Since the refrigerant liquid level height information by the liquid level measuring means and any one of the temperature information by the temperature measuring means or the pressure information by the pressure measuring means, the refrigerant leakage detecting means for detecting the refrigerant leakage is provided. Thus, it is possible to obtain a refrigeration cycle apparatus capable of detecting refrigerant leakage with high accuracy and early detection.

Further, the refrigeration cycle apparatus of the present invention is a refrigeration cycle apparatus having a compressor, a condenser, a liquid reservoir, an expansion means and an evaporator, or a refrigeration cycle apparatus having an auxiliary tank connected to the liquid reservoir, Since the liquid level measuring means for measuring the liquid level of the refrigerant in the liquid reservoir or the auxiliary tank is provided and is mounted outside the liquid reservoir or the auxiliary tank, the measurement is performed in the same manner as in the above claim 1. The construction is easy, and it can be easily mounted and measured in the liquid reservoir or auxiliary tank of a refrigerator already installed and operating. The surface temperature of the liquid reservoir or auxiliary tank, the refrigerant temperature in the liquid reservoir or auxiliary tank, the saturation temperature of the refrigerant in the condenser, or the condenser and the liquid reservoir or the liquid reservoir and the High pressure side temperature measuring means for measuring the refrigerant temperature of the pipe connecting the expansion means or high pressure side pressure measuring means for measuring the pressure of the refrigerant at any position in the flow path from the discharge side of the compressor to the expansion means And either the saturation temperature of the refrigerant in the evaporator, or the low pressure side temperature measuring means for measuring the refrigerant temperature in the flow path from the expansion means to the evaporator, or the flow path from the expansion means to the compressor Low pressure side pressure measuring means for measuring the pressure of the refrigerant at the position of the refrigerant, the refrigerant liquid level height information by the liquid level measuring means, any temperature information by the high pressure side temperature measuring means or the high Since the refrigerant leakage detecting means for detecting the refrigerant leakage is provided by pressure information by the side pressure measuring means and any temperature information by the low pressure side temperature measuring means or pressure information by the low pressure side pressure measuring means. It is possible to obtain a refrigeration cycle apparatus capable of detecting refrigerant leakage with high accuracy and early detection.

In the refrigeration cycle apparatus of the present invention, since the liquid level measuring means uses sound waves, ultrasonic waves, or vibrations, a sensor in the liquid reservoir or auxiliary tank can be provided without providing a sensor inside the liquid reservoir or auxiliary tank. Since the refrigerant liquid level can be measured from the outside, the sensor installation work can be facilitated, and the refrigerant can be installed in a refrigerator that is already installed and operating.

The refrigeration cycle apparatus of the present invention is a refrigeration cycle apparatus having a compressor, a condenser, a liquid reservoir, an expansion means, and an evaporator, and is a liquid level measuring means for measuring the refrigerant liquid level in the liquid reservoir. And the surface temperature of the liquid reservoir, the refrigerant temperature in the liquid reservoir, the saturation temperature of the refrigerant in the condenser, or the pipe connecting the condenser and the liquid reservoir or the liquid reservoir and the expansion means A high pressure side temperature measuring means for measuring the refrigerant temperature of the refrigerant, a high pressure side pressure measuring means for measuring the pressure of the refrigerant at any position in the flow path from the discharge side of the compressor to the expansion means, and in the evaporator The refrigerant saturation temperature or the pressure of the refrigerant at any position in the flow path from the expansion means to the compressor is measured by the low pressure side temperature measurement means for measuring the refrigerant temperature in the flow path from the expansion means to the evaporator. Low pressure side to measure Force measuring means, refrigerant liquid level height information by the liquid level measuring means, any temperature information by the high pressure side temperature measuring means or pressure information by the high pressure side pressure measuring means, and by the low pressure side temperature measuring means According to any one of the temperature information or the pressure information from the low-pressure side pressure measuring means, the refrigerant leakage detecting means for detecting the refrigerant leakage is provided. A cycle device can be obtained.

In the refrigeration cycle apparatus of the present invention, the remote monitoring means is wired or wirelessly connected to the refrigerant leak detection means. For example, the remote monitoring means is used by a company that manages a headquarter or facility that manages a store. Since it is provided in an office or the like and the refrigerant leakage can be constantly monitored, it is possible to detect the refrigerant leakage at an early stage and to take countermeasures at an early stage.

It is a block diagram of the refrigeration cycle apparatus in Embodiment 1 of this invention. It is a figure which shows the liquid reservoir of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a Mollier diagram which shows the operation | movement of the refrigerant | coolant of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a block diagram of the liquid level measurement means and refrigerant | coolant leak detection means which concern on Embodiment 1 of this invention. It is another block diagram of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. FIG. 5 is still another configuration diagram of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. It is the figure which showed the relationship between the condensation temperature which concerns on Embodiment 1 of this invention, evaporation temperature, and the refrigerant | coolant amount in a liquid reservoir. It is a flowchart which shows an example of the refrigerant | coolant leak detection algorithm which concerns on Embodiment 1 of this invention. It is a block diagram of the refrigeration cycle apparatus in Embodiment 2 of this invention. It is another block diagram of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention. It is a block diagram of the liquid level measurement means, refrigerant | coolant leak detection means, and remote monitoring means which concern on Embodiment 2 of this invention. It is a block diagram which shows the conventional refrigeration cycle apparatus. It is a block diagram which shows the other conventional refrigeration cycle apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Condenser, 4 Liquid reservoir, 6 Expansion means, 7 Evaporator, 9 High pressure gas piping, 10 Low pressure gas piping, 11 High pressure liquid piping of the inlet side of the liquid reservoir 4, 12 Outlet side of the liquid reservoir 4 High pressure liquid piping, 13 Refrigerant leak detection means, 15 Liquid level measurement means, 17 Store, 18 Showcase, 19 Refrigerator, 20 Network, 21 Remote monitoring means, 23 Transmitter, 24 Receiver, 25 Ultrasonic wave generation circuit, 26 Storage device, 27 timer, 28 computing device, 29 output device, 30 temperature measuring means, 30a, 30b temperature measuring means, 31a, 31b pressure measuring means, 40 input device, 41 computing device, 42 output device, 43 storage device, 44 Input device, 45 arithmetic device, 46 output device, 47 storage device.

Claims (9)

Calculating a refrigerant amount in the liquid reservoir from a refrigerant liquid surface position in the liquid reservoir of a refrigeration cycle in which a compressor, a condenser, a liquid reservoir, an expansion means, and an evaporator are connected by piping to circulate the refrigerant; Comparing the refrigerant amount related to the condensation temperature and evaporation temperature of the refrigeration cycle during normal operation with the newly calculated refrigerant amount, and determining the refrigerant leakage, and calculating the refrigerant amount in the liquid reservoir And a step of determining whether a certain time has elapsed after starting the compressor, and determining the refrigerant leakage by calculating the amount of the refrigerant based on the refrigerant liquid level position when it is determined that the certain time has elapsed after starting the compressor. A refrigerant leak detection method for a refrigeration cycle apparatus. 2. The refrigerant leakage detection method for a refrigeration cycle apparatus according to claim 1, wherein the refrigerant amount in the liquid reservoir is converted by obtaining a refrigerant density from a refrigerant condensation temperature. A refrigerant density is obtained from the refrigerant condensation temperature of a refrigeration cycle in which a compressor, a condenser, a liquid reservoir, an expansion means, and an evaporator are connected by piping to circulate the refrigerant, and the refrigerant amount in the liquid reservoir is determined. A step of calculating from the refrigerant liquid level position and the refrigerant density, and a step of determining refrigerant leakage by comparing the refrigerant amount stored in advance according to the condensation temperature and the refrigerant amount calculated during operation, A refrigerant leak detection method for a refrigeration cycle apparatus, characterized in that, when calculating the amount of refrigerant in a liquid reservoir, refrigerant leak is determined by calculation based on data after a predetermined time has elapsed since the start of the compressor. The refrigerant leakage detection method for a refrigeration cycle apparatus according to claim 1 or 3, wherein when the refrigerant leakage is determined, the refrigerant leakage is determined when the newly calculated refrigerant amount continues to decrease. . In the area where the newly calculated refrigerant amount is stored, it is determined whether or not the number of data obtained by calculating the refrigerant amount that has been learned and stored in the past is equal to or greater than a predetermined number, and if it is equal to or greater than the predetermined number, the refrigerant leakage is determined. The refrigerant leakage detection method for a refrigeration cycle apparatus according to claim 1 or 3, wherein A compressor, a condenser, a liquid reservoir, an expansion means, and an evaporator are connected by piping to refrigeration cycle for circulating the refrigerant, and the height of the fluctuating refrigerant liquid level in the liquid reservoir from which the refrigerant flows in from above. A liquid level measuring means for measuring, wherein the liquid level measuring means samples at a different frequency, or samples at a single frequency for a predetermined time, and averages the measured sampling data to obtain a liquid level height. A characteristic refrigeration cycle apparatus. 7. The refrigeration cycle apparatus according to claim 6, wherein the liquid level measured by the liquid level measuring means is lower than a simple average of measurement data. The refrigeration cycle apparatus according to claim 6 or 7, wherein the liquid level measuring means uses sound waves, ultrasonic waves, or vibrations. The liquid level measuring means is attached to the outside of the liquid reservoir or an auxiliary tank connected to the liquid reservoir, and measures the liquid level inside the liquid reservoir or the auxiliary tank. The refrigeration cycle apparatus described.

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