JP2003214734A - Control device of refrigerator and refrigerant leakage determination method for refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine a refrigerant leakage of a refrigerating cycle in a refrigerator without a gas leakage sensor. <P>SOLUTION: The load of a compressor 15 is varied due to leakage of a refrigerant to change the duty of the compressor. Accordingly, the duty of the compressor is monitored to surely determine the leakage of the refrigerant from a change of duty. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator / freezer control device and a refrigerant leakage determination method for a refrigerator / freezer.

[0002]

2. Description of the Related Art In recent years, interest in ozone layer protection and global warming has increased worldwide, and refrigerants used in refrigeration cycles have been reviewed. The majority of refrigerators on the market today use HFC refrigerants,
HFC refrigerant has a higher global warming potential than natural refrigerant.
Therefore, HC (hydrocarbon) is desired as a future refrigerant that does not cause ozone layer depletion and has a low global warming potential. However, since the HC refrigerant has flammability, it is necessary to take measures to reliably prevent the refrigerant from leaking, and if a refrigerant leak should occur, the refrigerant leak should be detected and ignited at the very early stage. It is necessary to have the necessary control to prevent it.

For example, in the technique disclosed in Japanese Patent Laid-Open No. 2000-146429, it is assumed that the refrigerant leaks and the refrigerant stays in the refrigerator, and the refrigerator operates even if the power plug is inserted during installation. Instead, the refrigerator is energized only when the power switch provided in the refrigerator is turned on. This is to prevent accidental accidents by discharging the HC refrigerant having a larger specific gravity than air by opening the door when the power switch is turned on, even if the refrigerant remains in the refrigerator.

In Japanese Patent Application No. 2001-228283, which is a patent application filed by the applicant of the present application, the refrigerant leak determination is performed by a gas sensor, and it is confirmed that the electric signal is zero, that is, there is no leakage of flammable refrigerant. It provides the technology to start operation for the first time later.

[0005]

However, in the prior art, in addition to the power switch, it is necessary to dispose a plurality of gas sensors in order to identify whether the leak location is on the low pressure side or the high pressure side, which greatly increases the cost. Become. Moreover, the gas sensor has a technical problem that it cannot be detected until a certain amount of gas concentration is reached due to refrigerant leakage.

The present invention has been made in view of the above-mentioned conventional technical problems, and in a refrigerating refrigerator using a flammable refrigerant, it is possible to reliably judge the refrigerant leakage without providing a gas leakage sensor. , It is possible to reduce the cost associated with the addition of the refrigerant leakage detection function, determine the refrigerant leakage from the behavior of the refrigeration cycle before the refrigerant leaks, and prevent the refrigerant gas concentration from reaching the ignition range when the refrigerant leaks. An object of the present invention is to provide a refrigerant leakage determination technique for a freezer / refrigerator.

[0007]

According to a first aspect of the present invention, there is provided at least two coolers arranged in parallel in a refrigerating room and a freezing room, respectively, and the refrigerant passage is installed upstream of all coolers. A refrigerating chamber, a freezer, which is provided with a switching valve that switches between the cooling units to supply the refrigerant to each cooler, a compressor that is provided on the refrigerant pipe and that compresses the refrigerant, and a controller that performs PID control of the frequency and duty of the compressor. The compressor and the switching valve are controlled so that the compressor is operated at a frequency calculated from the PID calculation based on the internal temperature of each room, and a refrigerating room and a freezing room are alternately cooled by using a combustible refrigerant as the refrigerant. A control device for a refrigerator / freezer, comprising: a duty measuring means for measuring the duty of the compressor; and a duty variation measured by the duty measuring means. It is obtained by a refrigerant leak judging means for judging the refrigerant leakage based on the rate.

According to the present invention, when leakage occurs in the refrigerant flowing according to the refrigerating cycle of the refrigerator-freezer,
Since the load of the compressor for flowing the refrigerant through the refrigerant flow path varies greatly, this load fluctuation is judged by measuring the duty of the PWM-controlled compressor, and the rate of change of this duty is outside the predetermined range. If it fluctuates, it is determined that there is a refrigerant leak.

According to a second aspect of the present invention, in the control device for a refrigerator / refrigerator according to the first aspect, the refrigerant leakage is determined by a change rate of the average value of the duty in the current cooling mode with respect to the average value of the duty in the same previous cooling mode. To do.

According to a third aspect of the present invention, in the control device for a refrigerator / refrigerator according to the first aspect, the duty at a predetermined point in the past is used as a reference duty, and refrigerant leakage is determined based on a rate of change from the current duty.

According to a fourth aspect of the present invention, in the refrigerator-freezer control device according to the third aspect, the duty at the time of the previous switching of the refrigerant flow path by the switching valve is used as the reference duty, and the refrigerant leakage is determined based on the current duty change rate. It is a thing.

According to a fifth aspect of the present invention, in the control device for a refrigerator-freezer according to the third aspect, the duty at the time when the frequency of the compressor is changed last time is used as a reference duty, and the refrigerant leakage is judged based on the current change rate of the duty. .

According to a sixth aspect of the present invention, in the refrigerator-refrigerator control device according to the first to fifth aspects, the refrigerant leakage determination means is configured such that, when the magnitude of the duty reduction rate exceeds a predetermined value, the high pressure side of the refrigeration cycle. It is determined that there is a refrigerant leak from.

When a hole is opened somewhere on the high pressure side of the refrigeration cycle, the pressure in the refrigerant passage is higher than the atmospheric pressure, so that the refrigerant is ejected from that portion and the pressure in the refrigeration cycle is reduced. As a result, the load on the compressor is reduced and the duty of the compressor is reduced. In view of this phenomenon, in the invention of claim 6, it is determined that refrigerant leakage has occurred on the high pressure side because the duty reduction rate of the compressor exceeds a predetermined value.

According to a seventh aspect of the present invention, in the refrigerator-freezer control device according to the first to fifth aspects, the refrigerant leakage determination means is a refrigerant leakage from the low pressure side when the duty increase rate exceeds a predetermined value. Is determined.

When a hole is opened somewhere on the low-pressure side of the refrigeration cycle, the pressure in that portion of the refrigerant passage is lower than atmospheric pressure, so the outside air is drawn in before the refrigerant leaks. For this reason, the pressure in the refrigeration cycle increases, the load on the compressor becomes heavy, and the duty increases. In view of this phenomenon, in the invention of claim 7, it is determined that refrigerant leakage has occurred on the low pressure side due to the increase rate of the duty of the compressor exceeding a predetermined value, and control for preventing refrigerant leakage can be performed. To do.

According to an eighth aspect of the present invention, in the control device for a refrigerator / freezer according to the first to fifth aspects, a refrigerant temperature sensor is provided at each inlet / outlet of the cooler for the freezer compartment, and the refrigerant leakage determination means is:
In addition to the duty change rate, the refrigerant leakage is determined based on the refrigerant temperature difference between the inlet and outlet of the freezer compartment cooler.

When the refrigerant leaks on the low pressure side of the refrigeration cycle, the temperature difference of the refrigerant at the inlet and outlet of the cooler becomes large as the duty changes. In view of this phenomenon, in the invention of claim 8, in addition to the change rate of the duty of the compressor, the leakage of the refrigerant from the low pressure side is determined when the temperature difference of the refrigerant at the inlet and outlet of the cooler becomes large.

According to a ninth aspect of the present invention, in the refrigerator-refrigerator control device according to the first to fifth aspects, the refrigerant leakage determination means has a duty reduction rate exceeding a predetermined value and a frequency increase value based on the PID calculation. When the value is exceeded, it is determined that there is a refrigerant leak from the high pressure side of the refrigeration cycle.

When the refrigerant leaks on the high pressure side of the refrigeration cycle, the refrigerant leaks to lighten the load on the compressor, while the refrigerant decreases to reduce the cooling capacity. Therefore, the frequency under the PID control increases in order to compensate for the insufficient cooling capacity with the operating frequency of the compressor. According to the ninth aspect of the present invention, such a rise in the PID calculated value is captured together with the change rate of the duty of the compressor, and the leakage of the refrigerant on the high pressure side is reliably determined.

According to a tenth aspect of the present invention, at least two coolers arranged in parallel in each of the refrigerating compartment and the freezing compartment and upstream of all the coolers are installed, and the refrigerating compartments are switched by switching the refrigerant passages. A switching valve for switching between a refrigerating chamber cooling mode for cooling and a freezing chamber cooling mode for cooling a freezing chamber, a compressor provided on the refrigerant pipe for compressing the refrigerant, and a frequency and a duty of the compressor depending on a load. And a controller for controlling the refrigerant, which is a refrigerant leakage determination method of a refrigerator-freezer for determining refrigerant leakage of a refrigerator-freezer that alternately cools a refrigerating compartment and a freezer compartment using a flammable refrigerant as the refrigerant, and compresses the refrigerant. The presence / absence of refrigerant leakage is determined by comparing the duty of the compressor to the duty in the same cooling mode of the previous time.

According to an eleventh aspect of the present invention, in the refrigerant leakage determination method for a refrigerator / freezer according to the tenth aspect, the duty of the compressor is the same as the duty at a predetermined timing after switching the cooling mode or starting the compressor in the same cooling mode of the previous time. It is to be compared with the timing duty.

The invention of claim 12 is based on claims 10 and 11.
In the refrigerant leakage determination method for a refrigerator / freezer, the duty of the compressor is compared with the frequency of the compressor kept constant.

According to a thirteenth aspect of the present invention, in the refrigerant leakage determination method for the refrigerator / freezer according to the tenth to twelfth aspects, when the duty reduction rate exceeds a predetermined value in the comparison of the duty of the compressor, the refrigerant from the high pressure side is reached. It is determined as a leak.

According to a fourteenth aspect of the present invention, in the refrigerant leakage determination method for a refrigerator / freezer according to the tenth to the twelfth aspect, when comparing the duty of the compressors, if the duty increase rate exceeds a predetermined value, the refrigerant from the low pressure side is discharged. It is determined as a leak.

According to a fifteenth aspect of the present invention, in the refrigerant leakage determination method for a refrigerator / freezer according to the tenth to fourteenth aspects, when the duty of the compressor is compared, the magnitude of the duty reduction rate exceeds a predetermined value or the duty increases. When the rate exceeds a predetermined value, the refrigerant leakage is determined while the frequencies of the switching valve and the compressor are fixed for a certain period of time.

According to the sixteenth aspect of the present invention, a refrigerator connected to each of the refrigerator and the freezer in parallel is arranged, and a refrigerant passage is switched upstream of both the refrigerators to cool the refrigerator. A freezer-refrigerator that determines a refrigerant leak in a freezer-refrigerator that has a switching valve that switches between a freezer compartment cooling mode and a freezer compartment cooling mode that cools the freezer compartment A refrigerant leakage determination method of
The duty of the compressor that compresses the refrigerant is compared with the duty in the same cooling mode of the previous time, and the temperature difference of the refrigerant at the inlet and outlet of the cooler for the freezer is measured, and the rate of increase of the duty becomes a predetermined value or more. When the temperature difference between the refrigerant at the inlet and outlet of the cooler exceeds a predetermined value, it is determined that the leak is on the low pressure side.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a cross-sectional view of a refrigerating refrigerator that employs the control device according to the first embodiment of the present invention, and FIG. 2 is an explanatory diagram of the refrigerating cycle thereof.

The refrigerator body 1 is composed of a heat insulating box 9 and an inner box 8, and is divided into a refrigerating temperature zone (refrigerating room R) 30 and a freezing temperature zone (freezing room F) 40 by a heat insulating partition wall 2 and is refrigerated. The cold air in the chamber 30 and the freezing chamber 40 are completely independent, and the cold air is not mixed with each other.

The inside of the refrigerator compartment 30 is divided into a refrigerator compartment 4 and a vegetable compartment 5 by a refrigerator partition plate 3, and the inside of the freezer compartment 40 is divided into a first freezer compartment 6 and a second freezer compartment 7. The opening / closing doors 51 to 54 are provided in the respective chambers.

On the back surface of the vegetable compartment 5, there are arranged a refrigerator refrigerator (R cooler) 10 composed of an evaporator and a refrigerator cooling fan 11. The refrigerator cooling fan 11 can be arbitrarily changed by changing the temperature inside the refrigerator or opening and closing the door. Be driven. On the rear surface of the cold storage room 4, a cold air circulation path 1 for supplying cold air into the cold storage room 30.
8 is formed.

On the back walls of the first and second freezer compartments 6 and 7, a freezer compartment cooler (F cooler) 12 and a freezer compartment cooling fan 13, which are also evaporators, are arranged to circulate cool air. The first and second freezer compartments 6 and 7 are cooled.

In the machine room 14 below the back wall of the refrigerator main body 1, a compressor (compressor) 15 and a condenser 21 constituting the refrigeration cycle shown in FIG. 2 are arranged. A three-way valve 22 serving as a switching valve is provided on the downstream side of the condenser 21. A refrigerating capillary 23 and an R cooler 10 are sequentially connected to one outlet of the three-way valve 22, and a freezing capillary 24, an F cooler 12 and an accumulator 16 are sequentially connected to the other outlet of the three-way valve 22. A check valve 17 is connected to the outlet pipe of the accumulator 16 in the machine chamber 14, and the outlet side of the check valve 17 joins the outlet pipe of the R cooler 10 and is connected to the suction side of the compressor 15. .

In the refrigerator / refrigerator having such a structure, the refrigerant flow path is switched by the three-way valve 22, and when cooling the freezing chamber 40, the refrigerant is decompressed by the freezing capillary 24 and enters the F cooler 12 to cool the freezing chamber 40. Then, it returns to the compressor 15 again, and when the refrigerating chamber 30 is cooled, the refrigerant is decompressed by the refrigerating capillary 23 and enters the R cooler 10,
After cooling the refrigerating chamber 30, the refrigerating cycle is returned to the compressor 15 again.

That is, the refrigerant during cooling of the freezer compartment is the freezing capillary 24, the F cooler 12, the accumulator 16,
The check valve 17 flows in this order, and the cold air circulates in the freezer compartment by the operation of the freezer compartment cooling fan 13, so that the first and second freezer compartments 6,
To cool. Then, when the three-way valve 22 is switched and the refrigerant flow path is switched from the freezing compartment 40 side to the refrigerating compartment 30 side, the refrigerant flows to the R cooler 10, and the refrigerating compartment fan 11 is operated to connect the refrigerating compartment 4 and the vegetable compartment 5. Cooling. The refrigerant used in this refrigeration cycle is, for example, a hydrocarbon-based combustible refrigerant (HC refrigerant) such as propane, isobutane, or a mixture thereof.

Here, isobutane (R
The case of using 600a) will be described. In the refrigeration cycle of FIG. 2, during cooling of the refrigerating chamber 30, the pressure and temperature of the R cooler 10 are about 0.11 MPa and −10 ° C.
So, the pressure and temperature of one F cooler 12 is about 0.05.
It becomes 5 MPa and -26 degreeC.

R cooler 10 and F cooler 12 during alternate cooling
The state of the pressure state and the temperature change of the cooler are as shown in FIG. In the cooling mode of the refrigerator compartment 30,
The pressure inside the cooler is higher on the refrigerating chamber 30 side than on the freezing chamber 40 side, the check valve 17 is closed due to this pressure difference, and the low temperature refrigerant is stored in the F cooler 12 (R cooling,). When this state is switched to the cooling mode of the freezer compartment 40, this low temperature refrigerant can be used for cooling.

In the cooling mode of the freezer compartment 40, the pressure and temperature of the F cooler 12 are about 0.055 MPa, -2.
At 6 ° C., the temperature of the R cooler 10 at this time is 0 ° C. to 2 ° C., but the pressure is 0.055 MPa, which is the same as that of the F cooler 12 (F cooling). Since the atmospheric pressure is about 0.1 MPa, the pressures of the F cooler 12 and the R cooler 10 are equal to or lower than the atmospheric pressure during the cooling mode (F cooling) of the freezer compartment 40.

As described above, by switching the three-way valve 22, the refrigerant passages are switched so as to alternately cool the refrigerating compartment 30 and the freezing compartment 40, and the refrigerating compartment cooling fan 11 is operated when cooling the refrigerating compartment. During cooling of the freezer compartment, each compartment is cooled by operating the freezer compartment cooling fan 13 to supply cold air. In addition, even when cooling the freezer compartment, the refrigerator compartment cooling fan 1
1 is for defrosting the refrigerating compartment cooler 10, so that it is operated up to a certain temperature.

When the refrigerant leaks, its position greatly differs between the high pressure side and the low pressure side of the refrigeration cycle. In other words, when the inside of the refrigerator is cooled to the normal temperature, the F cooler 12 has a temperature of -18 ° C.
At -26 ° C, the boiling point of isobutane is -11 ° C (1a
tm) or less. Further, even in the R cooler 10, the temperature becomes close to the boiling point when the refrigerating chamber is cooled. Therefore, the F cooler 12 and the R cooler 10, which are inside the refrigerator (low pressure side), have pinholes,
When a crack or the like occurs, the refrigerant is hardly released to the atmosphere during normal operation, and rather the outside air is sucked into the refrigeration cycle. On the other hand, since the refrigerant pressure becomes higher than the atmospheric pressure, on the high-pressure side, similar pinholes, cracks, etc., cause the refrigerant to immediately leak from the perforated part, and the refrigerant pressure in the refrigerant channel decreases. Become.

Therefore, in order to reliably determine the refrigerant leakage (including the refrigerant leakage prediction) when such a refrigerant leakage occurs or a situation in which the leakage may occur, the refrigeration cycle is required. It is necessary to divide the high pressure side and the low pressure side in the judgment method corresponding to each. FIG. 3 shows a functional configuration of the control device of the refrigerator / freezer that surely performs the refrigerant leakage determination.

The control device for the refrigerator-freezer shown in FIG. 3 has a refrigerating compartment temperature sensor 3 for detecting a temperature TH3 in the refrigerating compartment.
5, a freezer compartment temperature sensor 36 for detecting the temperature TH4 in the freezer compartment, a compartment temperature setting unit 101 for setting the compartment temperature, and a frequency calculator 1 for calculating the operating frequency of the compressor 15.
02, F cooler inlet sensor 31 that detects the inlet temperature TH1 of the cooler 12, and the cooler outlet sensor 32 that also detects the outlet temperature TH2, the temperature difference detection unit 103 that detects the temperature difference from the detected temperature. A main control unit 104 that controls the operation of the compressor 15 to perform temperature control and determines refrigerant leakage, a compressor drive unit 106 that drives the compressor 15 according to a command frequency and a duty from the main control unit 104, and a duty of the compressor 15 , A parameter measuring unit 105 for measuring the frequency. The controller 34 shown in FIG.
Is an inside temperature setting unit 101, a frequency calculation unit 102, a temperature difference detection unit 103, a main control unit 104, a parameter measurement unit 1
05, the compressor drive unit 106.

Next, the operation of the control device for the refrigerator-freezer according to this embodiment will be described. First, the temperature control of the refrigerating room and the freezing room, which is the basic function of the refrigerator-freezer, will be described.
The temperature control is based on the operating temperature and duty of the compressor 15 based on the internal temperature detected by the internal sensors 35 and 36 installed in the refrigerating room and the freezing room and the command value from the internal temperature setting unit 101. By adjusting.

The operating frequency of the compressor 15 is calculated by the following equation (1).

[0045]

[Equation 1] The calculation of the operating frequency is performed by the frequency calculating unit 102, and the main control unit 104 rounds the value of the calculated operating frequency into a plurality of predetermined frequencies and operates the compressor 15 at the frequency (command frequency). The parameter measuring unit 105 is the current compressor 15
Duty measurement is performed and is input to the main control unit 104. Temperatures TH1 and TH at the inlet and outlet of the F cooler 12
2 is detected by the cooler inlet sensor 31 and the outlet sensor 32, respectively, and the temperature difference detection unit 103 obtains the temperature difference between them and inputs them to the main control unit 104. Main controller 1
04 makes a refrigerant leak determination based on the duty of the compressor 15. The principle of determining the refrigerant leakage will be described.

Duty of the compressor 15 (ratio between micro power supply period and supply stop period in PWM control. Full power at 100%, half power at 50%, 0
% Is stopped) depends on the frequency (corresponding to the number of revolutions) of the compressor 15 and the load. Therefore, even if the load is constant, the duty changes depending on the frequency, and the degree of change of the duty with respect to the change of the load changes depending on the frequency. However, taking an arbitrary duty as a standard,
By calculating the change rate of the duty from the reference duty by the following formula 2, the load fluctuation can be observed regardless of the frequency.

[0047]

[Equation 2] Since there is a fixed relationship between the load on the compressor and the duty change rate, it is determined that there is refrigerant leakage if the calculated duty change rate deviates from a predetermined range. can do.

The reference duty may be the simplest, for example, "1 or 100%", but from the viewpoint of refrigerant leakage, a more preferable reference duty is set.

The reference duty is the duty at the timing when the duty changes regardless of the leakage of the refrigerant after the refrigeration cycle is switched or the operating frequency of the compressor 15 is switched. Then, the rate of change of the duty at that time point (current) with respect to the reference duty is calculated for every predetermined time from the equation 2, and the refrigerant leakage on the high-pressure side or the low-pressure side in the refrigerant flow path is determined based on it. In this case, the current duty of the compressor 15 is compared with the duty (reference duty) at the time of the previous same cooling to determine the refrigerant leakage.

As can be seen by comparing before and after the timing T0 in FIG. 10, the F cooler 12 which is the inside (low pressure side) of the refrigerator.
When a leak location such as a crack occurs in the R cooler 10 or the like, the refrigeration cycle draws in air due to the pressure difference from the atmosphere, and the pressure in the refrigeration cycle rises. The duty of the compressor 15 increases as the pressure increases. Usually, the duty in the refrigerating compartment cooling (R cooling) is higher than that in the freezing compartment cooling (F cooling). In FIG. 10, a leakage point is generated at T0 during F cooling, the duty is increased, and the duty is increased even after the R cooling is switched.

Although safety can be secured at an early stage if a leak determination can be made by increasing the duty of F cooling, it may not be possible to make a determination when cooling switching or compressor stop occurs. Therefore,
The main control unit 104 continuously monitors the measured value of the duty from the parameter measuring unit 105, and performs the R cooling at this time and the R cooling compressor 15 before the leakage (normal time).
The duty ratios are compared with each other, and if the increase rate of the duty reaches 10% or more on average for an arbitrary time, it is determined that the inside (low pressure side) leaks. Then, a warning of refrigerant leakage is issued, and in addition to the compressor 15, the electric parts inside the refrigerator are stopped and safely stopped.

As a result, when a pinhole or a hole such as a crack that causes a refrigerant leak occurs on the low pressure side of the refrigerant flow path of the refrigerator / freezer, an abnormality leading to a refrigerant leak occurs before the refrigerant leak by a simple procedure. It is possible to determine the occurrence of the above and take a countermeasure to prevent the refrigerant leakage.

Next, a refrigerant leakage determination method according to the second embodiment of the present invention will be described. The refrigerant leakage is determined by comparing the duty at a predetermined timing after switching the cooling mode or after starting the compressor 15 with the duty at the same timing during the previous cooling.

FIG. 11 compares the duty at the same timing T1 after the leakage occurs during the F cooling period and after the switching of the cooling mode by the control operation thereafter or after a lapse of a fixed time from the compressor start. Usually, immediately after switching the cooling mode or immediately after starting the compressor 15, the peak value is temporarily output, and the duty is not stable. Therefore, the previous duty (reference duty) and the current duty are compared immediately after switching the cooling mode or in a stable state where, for example, 2 minutes have passed since the compressor 15 was started. In this comparison, if the increase rate of the current duty from the reference duty is equal to or more than the predetermined value, it is considered that the load on the compressor 15 has increased due to the intake of the outside air, and it is determined that the refrigerant leakage has occurred on the low pressure side.

In this case, it is preferable to compare the duty of the compressor 15 under the condition that the frequency of the compressor 15 is constant. The duty of the compressor 15 in the normal state changes as the compressor frequency increases and decreases. Therefore, even if there is a request to change the frequency of the compressor during the arbitrary time for determining the refrigerant leakage, the refrigerant frequency can be more accurately determined by fixing the compressor frequency for a certain period until the leakage determination is completed.

Next, a refrigerant leakage determination method according to the third embodiment of the present invention will be described. The refrigerant leakage determination method according to the third embodiment is based on the duty change rate of the compressor 15, and when the duty reduction rate exceeds a predetermined value, the refrigerant leakage from the high pressure side of the refrigerant flow path is determined. It is a judgment. FIG. 12 shows a duty reduction process due to refrigerant leakage from the high pressure side.

If a pinhole, a crack or the like is formed on the high pressure side of the refrigerant flow path as described above, the refrigerant pressure is higher than the atmospheric pressure, so that the refrigerant leaks immediately. Therefore, the amount of the refrigerant in the refrigerant flow path is reduced, and the load on the compressor 15 is reduced. Therefore, it is determined that the refrigerant leakage has occurred on the high pressure side when the duty of the compressor 15 has decreased by a predetermined value or more from the duty at the same time last time. Then, if the refrigerant leakage is determined, an alarm for the outside of the refrigerator is issued, and the machine room fan 25 shown in FIG. 2 is operated to perform the safety response control for diffusing the refrigerant.

Even when the refrigerant on the high pressure side is judged, the judgment can be made more reliable by fixing the frequency of the compressor for a certain period of time. In order to improve the duty comparison accuracy, it is necessary to make the conditions such as the compressor frequency the same, and during the leakage determination processing by the main control unit 104, a change of a predetermined value or more in the duty was confirmed, and it was determined that there was a possibility of leakage. In this case, even if there is a switching request or a compressor frequency change request, the compressor frequency is fixed for a certain period of time until the refrigerant leakage determination is completed.

Next explained is a refrigerant leakage determination method according to the fourth embodiment of the invention. The feature of the fourth embodiment is that, in comparison of the duty of the compressor 15, when the duty becomes a predetermined value or more and the inlet / outlet temperature difference of the F cooler 12 becomes a predetermined value or more, it is determined to be a low-pressure side leak. Where it is. It has been known that when a refrigerant leak occurs, the difference between the inlet and outlet temperatures of the cooler increases as the duty changes. Therefore, by making the leak determination from the low pressure side at the time of both of these detections, the leak determination can be performed with higher accuracy as compared with the single determination of the duty.

Next, a description will be given of a refrigerant leakage judging method by the controller of the refrigerator / freezer according to the fifth embodiment of the present invention. FIG. 14 shows the state transition of the refrigerator / freezer when a relatively large refrigerant leak occurs on the high pressure side. As shown in the figure, when the refrigerant leaks on the high pressure side and the refrigerant sharply decreases,
The load on the compressor 15 is reduced. For this reason, the duty decreases, so that the current duty shows a large reduction rate of a predetermined value or more with respect to the reference duty based on the change rate calculated from the equation 2 (timing T1).
In 2), it can be determined that the refrigerant leaks on the high pressure side.

This makes it possible to detect refrigerant leakage under the same conditions even when the frequency of the compressor 15 is different.

Next, referring to FIG. 15, a refrigerant leakage determination method according to the sixth embodiment of the present invention will be described. The feature of the sixth embodiment is that the leakage of the high-pressure side refrigerant is determined by referring to the PID calculation result of the frequency of the compressor 15 together with the duty change rate.

FIG. 15 shows the state transition of the refrigerator / freezer when a relatively small refrigerant leak occurs on the high pressure side of the refrigerant flow path. Normally, the duty of the compressor 15 decreases when the inside of the refrigerator is sufficiently cooled from high temperature and the load is lightened. However, if the refrigerant leaks, as shown,
While the load on the compressor 15 is lightened, the cooling capacity decreases due to the decrease in the refrigerant, and the main control unit 104 increases the PID calculation result in an attempt to compensate for the insufficient cooling capacity by increasing the operating frequency of the compressor 15. In other words, even if the duty is reduced and cooling is in progress, a state mismatch occurs in which the operating rate of the compressor 15 is increased. Therefore, by detecting this state, it is possible to determine the occurrence of a relatively small refrigerant leak on the high pressure side.

For this reason, the frequency calculation unit 102 obtains the command frequency of the compressor 102 based on the difference between the inside temperatures TH3 and Th4 of the inside sensors 35 and 36 and the set temperature, and the main control unit 104 includes the parameter measurement unit. PID calculation is performed based on the difference between the frequency measured by 105 and the command frequency, and the rotation frequency and duty of the compressor 15 are controlled by pulse width modulation.

As the reference duty, a duty is set at a timing at which a constant duty is set regardless of refrigerant leakage, and the compressor 15 is set at the same timing.
The PID calculation result of the frequency for driving is used as the reference of the PID value. Then, the rate of change of the duty at that time with respect to the reference duty is obtained at every predetermined timing from the equation (2), and the calculation result of the PID is obtained.

If the magnitude of the duty reduction rate is greater than or equal to a predetermined value and the increase in the frequency PID calculation result is greater than or equal to the predetermined value, it is determined that the refrigerant leaks on the high pressure side. In this case, the predetermined value serving as the comparison criterion for the duty reduction rate is set smaller than that in the fifth embodiment. That is, the refrigerant leakage determination method of the fifth embodiment is effective when a relatively large refrigerant leakage occurs on the high pressure side and the duty change is large, and the refrigerant leakage determination method of the present embodiment is relatively effective. Even if a small refrigerant leak occurs on the high pressure side and the duty change is small, the refrigerant leak can be reliably determined.

Next, a refrigerant leakage determination method according to the seventh embodiment of the present invention will be described with reference to FIG. FIG. 13 shows that when a refrigerant leak occurs on the low pressure side (more accurately, at the stage before the refrigerant leak actually occurs, a pinhole is formed in the refrigerant flow path,
It shows the state transition of the refrigerator / freezer when a hole such as a crack occurs.

As shown in FIG. 13, for a while after the hole is formed in the low pressure side refrigerant flow path, the outside air is sucked in, the load becomes heavy, and the duty increases. F during cooling at the same time
The inlet / outlet temperature difference of the cooler 12 becomes larger than that in the normal time.
Therefore, as already described, the current duty change rate with respect to the reference duty is calculated, and the duty increase rate is equal to or higher than a predetermined value, and the inlet / outlet temperature difference of the F cooler 13 is equal to or higher than the predetermined value by that time. Is continued for a predetermined time or longer, it is determined that a refrigerant leak has occurred on the low pressure side.

It should be noted that there is a possibility that it may be erroneously detected as a variation due to the door opening / closing or the load of food becoming heavier only by the rate of increase of the duty, but the refrigerant leakage is accompanied by the opening / closing of the inlet / outlet temperature difference of the cooler. By determining the above, it is possible to make the determination of the refrigerant leakage on the low pressure side more reliable.

Although the refrigerant leakage determination method has been described above, the processing operation of the actual refrigerant leakage determination by the control device for the refrigerator-freezer shown in FIG. 3 will be described with reference to the flowcharts of FIGS. 4 to 9.

FIG. 4 is a flow chart showing the procedure of the determination process of the duty check timing. This duty check timing determination process prevents the load from being falsely detected as a refrigerant leak when the load is temporarily lightened, such as when the power is turned on, during pull-down, defrosting, and forced cooling, and when the duty fluctuation is large. Run to This process is executed every fixed control cycle.

First, when the processing is started, it is judged whether or not the power is turned on (S1). If the power is turned on here (S1: YES), the number of freezing room cooling is cleared ( S12), and subsequently the refrigerant leakage detection operation is prohibited (S13). Then, the storage of the duty data is cleared (S15), and the process is terminated without checking the duty (S16).

In step S1, the power is not turned on but the operation is in progress (S1: NO), the pulldown is not in progress (S2: NO), and the defrosting is not in progress (S3: N).
O), if it is not in the forced cooling (S4: NO), it is determined whether or not the freezing room cooling frequency has ended twice (S).
5).

If it is determined in step S5 that the freezing compartment cooling has not been completed twice (S5: NO), the freezing compartment temperature is not stable and the refrigerant leakage detection operation is prohibited (S5).
13). On the other hand, in step S5, when it is determined that the freezing room cooling frequency has ended twice (S5: YE
S), leak detection is performed (S6).

In order to carry out this leak detection, it is first determined whether or not the refrigerating compartment is being cooled (S7). If it is not refrigerating compartment cooling (S7: NO), it is determined whether or not the freezing compartment is being cooled. Yes (S14).

When the refrigerating chamber is being cooled (S7: YES) or the freezing chamber is being cooled (S14: YES), it is subsequently determined whether or not the compressor 15 is in operation (S8). Here, when the compressor 15 is not starting and is in a stable operating state (S8: NO), it is subsequently determined whether the refrigeration cycle is switched by the three-way valve 22 (S9).

If it is not immediately after the switching of the refrigeration cycle (S9: NO), it is judged whether it is immediately after the drive frequency of the compressor 15 is changed (S10). S10: N
O), the duty is checked (S11).

By the above processing, when the refrigerator door is opened or closed or the load in the refrigerator is increased, the frequency is switched by the frequency calculation of the compressor 15. However, if such a variation is large, the duty check is temporarily suspended. Will be done. In addition, the duty changes regardless of the refrigerant leakage during the startup of the compressor 15 or when the frequency is changed by changing the command frequency, and immediately after switching the refrigeration cycle. Therefore, the duty check is also performed at these timings. Will not be. Therefore, erroneous detection of refrigerant leakage in these cases can be eliminated.

FIG. 5 is a flow chart showing the processing procedure of duty sampling. In order to cancel the measurement error and the like, the duty is sampled every 16 seconds (S21 to S24), and the average value is calculated approximately every 1 minute. Then, if it is a condition for performing a duty check at the time when this average value is calculated, a duty check timing command is output (S25, S26).

FIG. 6 is a flow chart showing the procedure for checking the inlet / outlet temperature difference of the F cooler 12 on the freezer side. This process is repeated every predetermined period, in addition to the duty sampling process described above.

First, it is determined whether or not the freezing compartment is being cooled (S).
31). Here, if the freezing room is not being cooled (S31: N
O), it is determined that there is no inlet / outlet temperature difference (S37), and the process ends. On the other hand, when the freezer compartment is being cooled (S31: YE
S), the temperature difference detection unit 103 obtains the inlet / outlet temperature difference from the temperature measurement results TH1 and TH2 of the cooler inlet sensor 31 and the outlet sensor 32. Then, it is determined whether the inlet / outlet temperature difference exceeds 6 ° C. (S32), and if the temperature difference exceeds 6 ° C. (S32: YES), it is determined whether or not this state continues for 20 minutes or more. It is determined (S33), and if this state continues for 20 minutes or more, the determination that there is a temperature difference is output (S34). Further, when the inlet / outlet temperature difference is 6 ° C. or more, but has not continued for 20 minutes or more (S33: N
O), there is a possibility that the freezer compartment cooling will end during the time determination of 20 minutes, so at the end of the freezer compartment cooling, the temperature difference 6
If the temperature exceeds ℃ for 5 minutes or more (S35: Y
ES, S36: YES), it is considered that the same state will continue in the future, and it is determined that there is a temperature difference (S34). Under other conditions, it is determined that there is no difference in inlet / outlet temperature (S3
7).

By this process, in principle, when the temperature difference exceeds 6 ° C. for 20 minutes or more, it is judged that the refrigerant is actually leaked and the refrigerant is leaking.

FIG. 7 is a flowchart of the duty increase determination process. This processing is also repeatedly executed at predetermined intervals. Only when the condition of the duty check is satisfied in step S11 described above, the duty increase determination is performed (S41: YES), and the second minute (the second minute after reset) after the duty data is cleared. It is determined whether there is any (S42). As a result of this judgment, 2
If it is the minute (S42: YES), the duty at that time is stored as the reference duty, and in this case, the processing is ended without performing the duty increase determination (S46, S4).
7).

On the other hand, if it is determined in step S42 that it is not the second minute after the reset (S42: NO), it is determined whether or not it is the third minute or more after the reset (S43). Then, if it is after the third minute (S43: YES), it is determined whether or not the increase rate of the current duty with respect to the reference duty exceeds 10% (S44). Here, if the duty increase rate exceeds 10% (S44: YES), a determination that there is a duty increase is output (S45).

In this duty increase determination, the duty at the second minute from the start of the duty check is used as a reference. Here, the reason why the value is not set to the first minute is that it takes several tens of seconds to stabilize the duty, and the average value may not be calculated correctly. And from the third minute onwards,
The current duty is compared with the reference duty using the duty of the second minute as the reference duty, and it is determined that the duty has increased when the change rate calculated from the equation 2 exceeds 10%.

Usually, the duty change rate due to opening / closing of the refrigerator door or load fluctuation in the refrigerator or freezer is 10% or less. When the load fluctuation is large, the duty check is reset by calculating the command frequency by frequency calculation. It

FIG. 8 is a flowchart of the refrigerant leak determination processing on the low pressure side. In this process, first, it is determined whether or not the leakage detection prohibition in step S13 described above is issued (S51). Here, if the leakage detection prohibition is issued (S51: YES), there is no need to make this determination, and the process is terminated as it is.

On the other hand, if the leakage detection prohibition is not issued (S51: NO), in the above-mentioned step S34, F
It is determined whether or not it is determined that the refrigerant temperatures at the inlet and outlet of the cooler 12 have a difference of a predetermined value or more (S52). Here, if it is determined that there is a difference in inlet / outlet temperature (S52: Y
ES), and subsequently, it is determined whether or not it is determined in step S45 that the duty is increased (S5).
3). If it is determined that there is an increase in duty (S53: YES), it is determined that there is refrigerant leakage on the low pressure side, and the low pressure side leakage is determined (S54).

As described above, it is determined that there is a refrigerant leak on the low pressure side when the inlet / outlet temperature difference of the F cooler 12 is equal to or more than a predetermined value and the duty of the compressor 15 is determined to increase. . With this, it is possible to determine the refrigerant leakage in advance in a state where the outside air suction before the refrigerant leakage occurs with the relatively small hole.

In the flowchart of the low-pressure side leak determination processing, the step of determining the cooler temperature difference in step S52 is skipped, and it is determined in step S53 that the current duty increase rate with respect to the reference duty is equal to or higher than a predetermined value. If so, it can be simplified to determine that low-pressure side leakage has occurred. However, the predetermined value for comparing the rate of increase in duty in this case is set to a larger value than in the case where the temperature difference determination is also performed.

FIG. 9 is a flow chart showing the processing for the duty reduction determination and the high pressure side leakage determination. In this process, first, a duty reduction determination is performed. for that reason,
In step S12, it is determined whether the duty check condition is satisfied (S61). Here, if the condition of the duty check is not satisfied (S61: NO), the process is ended without determining the duty reduction (S70).

On the other hand, if the duty check condition is satisfied (S61: YES), then the duty and the frequency of the compressor 15 at that time are stored (S62). Subsequently, it is determined whether or not it is the first minute after the storage of the duty data in step S15 is cleared (S63). As a result of this determination, if it is the first minute (S63: YES), the duty is not reduced (S7).
0).

If it is not the first minute in step S63 (S6
3: NO), and subsequently, it is determined whether or not it is 10 minutes or more after the reset (S64). If 10 minutes or more have not elapsed after the reset (S64: NO), it is determined that the duty reduction is not determined (S70).

On the other hand, if 10 minutes or more have elapsed after the reset (S64: YES), it is subsequently determined whether the duty reduction rate exceeds 15% (S65). If the duty reduction rate does not exceed 15% (S65: NO), the duty reduction rate is 10%.
It is determined whether or not it exceeds% (S68). In this determination, if the duty reduction rate does not exceed 10% (S66: NO), the duty reduction is not determined (S66: NO).
70).

On the other hand, although 10 minutes or more have passed since the reset (S64: YES), the duty reduction rate is 10%.
Within the range of ˜15% (S65: NO, S68: YE
S) If the current command frequency is higher than the command frequency 10 minutes ago, it is determined that refrigerant leakage has occurred on the high pressure side (S69: YES, S67).

When the duty reduction rate exceeds 15% in step S65 (S65: YE
S), it is determined that refrigerant leakage has occurred on the high pressure side without considering the change in frequency (S67).

In this process, the average value of the calculated duty change rates in the first minute is not used. And 2
The duty is recorded every minute after the minute, and after 10 minutes or more, the present and 10 minutes before are compared, and when the change rate calculated from the equation 2 exceeds 15%, the duty is changed. It is determined that the pressure has decreased, and it is continuously determined that the leakage is on the high pressure side. Here, the reason why the duty is determined to decrease when the duty fluctuation rate exceeds 15% is that the duty may normally fluctuate by about 15% in 30 to 40 minutes of freezing room cooling.

If the duty is reduced in the range of 10% to 15%, it is determined that the refrigerant leak has occurred on the high pressure side if the current command frequency is higher than the command frequency 10 minutes ago. is doing. It should be noted that there is no error in the set temperature that is the calculation source of the frequency that drives the compressor 15, and the internal cold storage temperature is not always the same temperature. There is no particular need to set a threshold value for determining the increase of the command frequency.

As described above, according to the present embodiment, the leakage of the refrigerant from the refrigeration cycle can be reliably detected. Therefore, when the flammable refrigerant is used as the refrigerant, the leakage of the refrigerant is detected. At that time, it is possible to prevent ignition by stopping the operation of electrical parts that may become the ignition source, and sound an alarm so that the ignition source etc. will not be accidentally brought near the refrigerator. The user can be notified of the flammable refrigerant leakage.

Although the embodiment of the refrigerator / freezer to which the present invention is applied has been described above, the present invention is not limited to the refrigerator / freezer. The present invention can be applied not only to a single function such as a refrigerator or a freezer but also to all cooling devices using a refrigerant such as an air conditioner within the scope of the technical idea. In addition, the principle of heat transfer is exactly the same in a heat cycle where the inside is warmed, such as a heat pump cycle, so the present invention can be applied to a heat pump cycle.

[0101]

As described above, according to the control device for a refrigerator-freezer of the invention of claim 1, when the refrigerant flowing according to the refrigerating cycle of the refrigerator-freezer leaks, the refrigerant is passed through the refrigerant passage. Since the load of the compressor for causing the current to flow greatly fluctuates, this load fluctuation is judged by measuring the duty of the PWM-controlled compressor, and if the rate of change of this duty fluctuates outside the prescribed range, refrigerant leakage occurs. By determining that there is, it is possible to perform a highly reliable determination of refrigerant leakage without using a gas sensor or the like.

According to the refrigerator-refrigerator controller of the second aspect of the present invention, the refrigerant leakage is determined by the rate of change of the average duty value in the current cooling mode with respect to the average duty value in the same cooling mode of the previous time. It is possible to determine the refrigerant leakage with high reliability without being affected by the instantaneous fluctuation of the duty.

According to the control device of the refrigerator / freezer of the present invention, the duty at a predetermined time in the past, the duty at the time of the previous switching of the refrigerant flow path by the switching valve, or the time of the last frequency change of the compressor. Since the duty is used as a reference duty and the refrigerant leakage is determined based on the current change rate of the duty with respect to the reference duty, the duty change of the compressor can be accurately captured, and the refrigerant leakage can be determined with high reliability.

According to the control device of the refrigerator / freezer of the sixth aspect of the present invention, the leakage of the refrigerant on the high pressure side can be accurately determined.

According to the refrigerator-refrigerator control device of the seventh aspect of the present invention, it is determined that refrigerant leakage has occurred on the low pressure side due to the increase rate of the duty of the compressor exceeding a predetermined value. A pinhole in the refrigerant flow path on the side, a hole such as a crack is generated, and it is possible to determine the refrigerant leakage occurrence in the state where the outside air is started to be sucked in,
Control can be performed to prevent refrigerant leakage.

According to the refrigerator-refrigerator controller of the eighth aspect of the present invention, the leakage from the low pressure side of the refrigerant is determined based on the duty change rate of the compressor and the temperature difference of the refrigerant at the inlet and outlet of the cooler. It is possible to reliably determine the occurrence of refrigerant leakage at the very early stage when the perforation of the pipe occurs and the outside air is sucked in.

According to the control device for a refrigerator / freezer of the invention of claim 9, it is possible to reliably detect the leakage of the refrigerant on the high-pressure side by catching the rate of change of the duty of the compressor and the rise of the calculated PID value of the compressor. it can.

According to the refrigerant leakage determination method for a refrigerator / freezer of the tenth aspect of the present invention, the presence or absence of refrigerant leakage is determined by comparing the duty of the compressor for compressing the refrigerant with the duty in the previous same cooling mode. It is possible to make a highly reliable refrigerant leak determination without using.

According to the refrigerant leakage determination method for a refrigerator / freezer of the invention of claim 11, the duty at a predetermined timing after switching the cooling mode or after starting the compressor is compared with the duty at the same timing in the previous same cooling mode. Since the refrigerant leakage is determined, the refrigerant leakage can be determined by comparing the current duty with the duty in a stable system as a reference, and highly reliable refrigerant leakage determination can be performed.

According to the refrigerant leakage determination method for a refrigerator / freezer of the twelfth aspect of the present invention, the duty ratios of the compressors are compared with each other while the frequency of the compressors is kept constant. Refrigerant leakage can be determined by purely catching the duty fluctuation caused by refrigerant leakage, and highly reliable refrigerant leakage determination can be performed.

According to the refrigerant leak judging method for a refrigerator / freezer of the thirteenth aspect, it is judged that the refrigerant leaks from the high pressure side when the reduction rate of the duty of the compressor exceeds a predetermined value. The occurrence of refrigerant leakage from the high pressure side of the refrigeration cycle can be reliably determined.

According to the refrigerant leak judging method for a refrigerator / freezer of the fourteenth aspect of the invention, it is judged that the refrigerant leaks from the low pressure side when the increase rate of the duty of the compressor exceeds a predetermined value, so that the gas sensor is not used. In addition, it is possible to reliably determine the occurrence of refrigerant leakage in a state in which it cannot be detected even if the gas sensor is set, that is, in the initial state in which the low pressure side pipe is pierced and sucks the outside air.

According to the refrigerant leakage determination method of the refrigerator / freezer of the fifteenth aspect of the present invention, when the magnitude of the duty reduction rate of the compressor exceeds a predetermined value or the duty increase rate exceeds a predetermined value, the switching valve Since refrigerant leakage is determined while the frequency of the compressor is fixed for a certain period of time, highly reliable determination of refrigerant leakage can be performed.

According to the refrigerant leakage determination method of the refrigerator / freezer of the sixteenth aspect of the present invention, the duty increase rate of the compressor is equal to or higher than a predetermined value, and the temperature difference between the refrigerant at the inlet and outlet of the cooler is equal to or higher than the predetermined value. Sometimes it is judged that the leak is on the low pressure side, so it is not possible to detect without using the gas sensor and even if the gas sensor is set, that is, the low pressure side pipe is pierced and the outside air is sucked in. It is possible to reliably determine the occurrence of a refrigerant leak in the very early stage when it becomes.

[Brief description of drawings]

FIG. 1 is a sectional view of a refrigerator-freezer to which a control device according to an embodiment of the present invention is applied.

FIG. 2 is an explanatory diagram of a refrigerating cycle of the above-mentioned refrigerator / freezer.

FIG. 3 is a block diagram showing a functional configuration of a control device for the refrigerator-freezer according to the above embodiment.

FIG. 4 is a flowchart of determination processing of duty check timing according to the above embodiment.

FIG. 5 is a flowchart of duty sampling processing according to the above embodiment.

FIG. 6 is a flowchart of a process for checking the refrigerant temperature difference between the inlet and outlet of the cooler according to the above embodiment.

FIG. 7 is a flowchart of a duty increase determination according to the above embodiment.

FIG. 8 is a flowchart of a refrigerant leak determination on the low pressure side according to the above embodiment.

FIG. 9 is a flowchart for determining duty reduction and refrigerant leakage determination on the high pressure side according to the above-described embodiment.

FIG. 10 is a graph showing the behavior of the duty of the compressor when holes are formed on the low-pressure side of the refrigerator / freezer, and the refrigerant leakage determination method according to one embodiment of the present invention.

FIG. 11 is a diagram showing the behavior of the duty of the compressor when holes are formed on the low pressure side of the refrigerator / freezer and a refrigerant leakage determination method according to another embodiment of the present invention.

FIG. 12 is a diagram showing a duty behavior of the compressor when a refrigerant leak occurs on the high pressure side of the refrigerator / freezer and a refrigerant leak determination method according to still another embodiment of the present invention.

FIG. 13 is a graph showing the duty of the compressor, the behavior of the temperature of each part when holes are formed on the low pressure side of the refrigerator / freezer, and the refrigerant leakage determination method according to still another embodiment of the present invention.

FIG. 14 shows the duty of the compressor and the behavior of the temperature of each part when a refrigerant leak occurs on the high pressure side of the refrigerator / freezer;
The figure which shows the refrigerant leak determination method of other embodiment of this invention.

FIG. 15 is a diagram showing the behavior of the duty of the compressor, the temperature of each part, and the PID value when a refrigerant leak occurs on the high-pressure side of the refrigerator / freezer, and a refrigerant leak determination method according to still another embodiment of the present invention.

[Explanation of symbols]

1 Refrigerator body 10 Refrigerator cooling device (R cooling device) 12 Freezer compartment cooler (F cooler) 15 Compressor 21 condenser 22 three-way valve 30 Refrigerator 31 Cooler inlet sensor 32 Cooler outlet sensor 34 Controller 35 Cold room sensor 36 Freezer compartment sensor 40 Freezer 101 Internal temperature setting unit 102 Frequency calculator 103 Temperature difference detector 104 Main control unit 105 Parameter measurement unit 106 Compressor drive unit

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[Procedure amendment]

[Submission date] January 20, 2003 (2003.1.2
0)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 10

[Correction method] Change

[Correction content]

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 16

[Correction method] Change

[Correction content]

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

According to a first aspect of the present invention, at least two coolers arranged in each of a refrigerating room and a freezing room are installed upstream of all coolers, and a refrigerant flow path is switched. A cooling valve for supplying refrigerant to each cooler, a compressor provided on the refrigerant pipe for compressing the refrigerant, and a controller for PID controlling the frequency and duty of the compressor, and each of the refrigerating room and the freezing room. Refrigerator / refrigerator that controls the compressor and the switching valve so that the compressor is operated at a frequency calculated from PID calculation based on the internal temperature of the refrigerator, and a combustible refrigerant is used as the refrigerant to alternately cool the refrigerating compartment and the freezing compartment. Of the duty ratio of the duty measured by the duty measuring means and the duty measuring means for measuring the duty of the compressor. It is obtained by a refrigerant leak determination means for determining a leakage of the refrigerant Zui.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

According to a tenth aspect of the present invention, at least two coolers arranged in each of the refrigerating compartment and the freezing compartment and upstream of all the coolers are installed, and the refrigerant passages are switched to cool the refrigerating compartment. A switching valve for switching between a refrigerating compartment cooling mode and a freezing compartment cooling mode for cooling the freezing compartment, a compressor provided on the refrigerant pipe for compressing the refrigerant, and controlling the frequency and duty of the compressor according to the load. A refrigerant leakage determination method for a refrigerator / refrigerator for determining refrigerant leakage in a refrigerator / freezer that alternately cools a refrigerating compartment and a freezer compartment by using a combustible refrigerant as the refrigerant, the compressor compressing the refrigerant. The duty of is compared with the duty in the same cooling mode of the previous time, and the presence or absence of refrigerant leakage is determined.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

In the sixteenth aspect of the present invention, a cooler is arranged in each of the refrigerating chamber and the freezing chamber, and a refrigerating chamber cooling mode and a freezing chamber for cooling the refrigerating chamber by switching the refrigerant passages upstream of both the coolers are provided. A refrigerant leak determination method for a refrigerator / freezer that determines a refrigerant leak in a refrigerator / freezer in which a combustible refrigerant is used as a refrigerant to cool the refrigerating compartment and the freezer compartment alternately by providing a switching valve for switching the mode The duty of the compressor for compressing the refrigerant is compared with the duty in the previous same cooling mode, and the temperature difference of the refrigerant at the inlet and outlet of the cooler for the freezer is measured, and the increase rate of the duty is predetermined. When the temperature is equal to or higher than the value and the temperature difference between the refrigerant at the inlet and outlet of the cooler is equal to or higher than the predetermined value, it is determined that the leak is on the low pressure side.

Continued front page    (72) Inventor Ryosuke Yamamoto             No. 6 Ota-Toshiba-cho, Ibaraki City, Osaka Prefecture Stock Association             Company Toshiba Osaka factory (72) Inventor Tsutomu Sakuma             No. 6 Ota-Toshiba-cho, Ibaraki City, Osaka Prefecture Stock Association             Company Toshiba Osaka factory (72) Inventor Yoshihiko Uenoyama             No. 6 Ota-Toshiba-cho, Ibaraki City, Osaka Prefecture Stock Association             Company Toshiba Osaka factory (72) Inventor Shoji Hashimoto             No. 6 Ota-Toshiba-cho, Ibaraki City, Osaka Prefecture Stock Association             Company Toshiba Osaka factory (72) Inventor Shinji Hirai             No. 6 Ota-Toshiba-cho, Ibaraki City, Osaka Prefecture Stock Association             Company Toshiba Osaka factory F-term (reference) 3L045 BA01 CA03 DA02 EA01 PA03

Claims (16)

[Claims] 1. At least two coolers arranged in parallel in a refrigerating room and a freezing room, respectively, and installed on the upstream side of all coolers, and switching the refrigerant flow paths to supply the refrigerant to each cooler. A switching valve, a compressor provided on the refrigerant pipe, for compressing the refrigerant, and a controller for PID controlling the frequency and duty of the compressor are provided. A controller of a refrigerator / freezer for controlling the compressor and the switching valve so as to alternately cool the refrigerating room and the freezing room by operating the compressor at the calculated frequency and using a combustible refrigerant as the refrigerant, A duty measuring means for measuring the duty of the refrigerant, and judging the refrigerant leakage based on the duty change rate measured by the duty measuring means. Control device for refrigerator, characterized in that a refrigerant leak determination means. 2. The refrigerator / freezer according to claim 1, wherein the duty change rate is a change rate of an average duty value in a current cooling mode with respect to an average duty value in a previous same cooling mode. Control device. 3. The change rate of the duty is a change rate of the current duty with the duty at a predetermined point in the past as a reference duty.
The control device for the refrigerator-freezer described. 4. The control device for a refrigerator / refrigerator according to claim 3, wherein the reference duty is set at a time point when the switching valve previously switched the refrigerant flow path. 5. The control device for a refrigerator / freezer according to claim 3, wherein the reference duty is a value at a time when the frequency of the compressor last changed. 6. The refrigerant leakage determination means determines that the refrigerant leakage is from the high pressure side of the refrigeration cycle when the magnitude of the duty reduction rate exceeds a predetermined value. The control device for the refrigerator-freezer according to any one of 1 to 5. 7. The refrigerant leakage determination means determines that there is a refrigerant leakage from the low pressure side of the refrigeration cycle when the increase rate of the duty exceeds a predetermined value. The control device for the refrigerator-freezer according to any one of 1. 8. A refrigerant temperature sensor is provided at each of the inlet and outlet of the freezer compartment cooler, and the refrigerant leakage determination means has a duty increase rate exceeding a predetermined value, and the refrigerant at the inlet and outlet openings of the freezer compartment cooler. When the temperature difference exceeds a predetermined value, it is determined that there is a refrigerant leak on the low pressure side of the refrigeration cycle.
The control device for the refrigerator-freezer according to any one of 1. 9. The refrigerating cycle high-pressure side of the refrigeration cycle, when the magnitude of the duty reduction rate exceeds a predetermined value and the frequency increase value based on the PID calculation exceeds a predetermined value. The control device for the refrigerator-freezer according to any one of claims 1 to 5, wherein it is determined that there is a refrigerant leak from the refrigerator. 10. A refrigerating compartment cooling mode and a refrigerating compartment cooling mode in which coolers are connected in parallel to the refrigerating compartment and the freezing compartment, and the refrigerating compartment is cooled by switching a refrigerant passage upstream of both coolers. A refrigerant leak determination method for a refrigerator / freezer that determines a refrigerant leak in a refrigerator / freezer in which a combustible refrigerant is used as a refrigerant to cool the refrigerator compartment and the freezer compartment alternately by providing a switching valve for switching between the freezer compartment cooling mode for cooling A method for judging refrigerant leakage in a refrigerator / refrigerator, characterized by comparing the duty of a compressor for compressing the refrigerant with the duty in the same cooling mode of the previous time to judge the presence or absence of refrigerant leakage. 11. The refrigeration according to claim 10, wherein the duty of the compressor compares a duty at a predetermined timing after switching the cooling mode or after starting the compressor with a duty at the same timing in the previous same cooling mode. Refrigerant leak determination method for refrigerators. 12. The refrigerant leakage determination method for a refrigerator-freezer according to claim 10, wherein the duty of the compressor is compared with the frequency of the compressor kept constant. 13. The refrigerant leakage from the high pressure side is determined when the magnitude of the duty reduction rate exceeds a predetermined value in the comparison of the duty of the compressor. The refrigerant leakage determination method for a refrigerator-freezer as described. 14. The refrigerating machine according to claim 10, wherein when the duty ratio of the compressor exceeds a predetermined value, it is determined that the refrigerant leaks from the low pressure side. Refrigerant leak determination method for refrigerators. 15. When comparing the duty ratios of the compressors, if the magnitude of the duty reduction rate exceeds a predetermined value or the duty rise rate exceeds a predetermined value, the switching valve and the compressor frequency are fixed for a certain period of time. The refrigerant leakage determination method for a refrigerator-freezer according to any one of claims 10 to 14, wherein: 16. A refrigerating chamber cooling mode and a refrigerating chamber cooling mode, in which a cooling device connected in parallel to each of the refrigerating chamber and the freezing chamber is arranged, and a refrigerant flow path is switched upstream of both cooling devices to cool the refrigerating chamber. A refrigerant leak determination method for a refrigerator / freezer that determines a refrigerant leak in a refrigerator / freezer in which a combustible refrigerant is used as a refrigerant to cool the refrigerator compartment and the freezer compartment alternately by providing a switching valve for switching between the freezer compartment cooling mode for cooling The duty of the compressor for compressing the refrigerant is compared with the duty in the previous same cooling mode, and the temperature difference of the refrigerant at the inlet and outlet of the cooler for the freezer is measured, and the increase rate of the duty is predetermined. A refrigerant leak determination method for a refrigerator / freezer, wherein when the temperature difference is equal to or higher than a value and the temperature difference between the refrigerant at the inlet and outlet of the cooler is equal to or higher than a predetermined value, it is determined that there is a refrigerant leak on the low pressure side.