JPH11230623A - Freezer and its operation control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of oil shortage or defective lubrication caused by the repetition of short-time operation of a compressor. SOLUTION: A discharge pipe 24 led out of the discharge side of a compressor 14 is connected to the inlet side of a condenser 16, and a refrigerant pipe 26 led out of the condenser 16 is connected to the inlet side of an evaporator 12 through an expansion valve 10. A suction pipe 28 led out of the outlet side of the evaporator 12 is connected to the suction side of the compressor 14. The expansion valve 10 is opened and closed, according to the information on the refrigerant temperature on low pressure side detected by a temperature sensitive tube 30 arranged in the suction pipe 28. A bypass pipe 34 branched from the refrigerant supply pipe 26 between the condenser 16 and the expansion valve 10 is led and connected to the suction pipe 28 through a solenoid valve 36 and a capillary tube 38 inserted in series. The solenoid valve 36 is opened and closed, according to the information on the room temperature detected by an in-room thermostat 20 arranged inside the freezing room 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus provided with a large-capacity compressor for a load in a refrigerator, and a method for controlling the operation of the refrigerating apparatus.

[0002]

2. Description of the Related Art In a quick-freezing refrigerator for rapidly freezing stored items stored in a refrigerator, a refrigerating device having a large-capacity compressor with respect to the load in the refrigerator is used. FIG. 9 is a schematic diagram showing a refrigeration apparatus according to the related art. The refrigeration apparatus includes an expansion valve 10 that expands a high-pressure liquefied refrigerant into a vaporized refrigerant,
The evaporator 12 performs a cooling operation by the heat of vaporization taken when the liquefied refrigerant is vaporized, the compressor 14 that sends the vaporized refrigerant having performed the cooling operation in the evaporator 12 to the condenser in a compressed state, and A condenser 16 is built in which the vaporized refrigerant compressed by the compressor 14 is condensed to become a liquefied refrigerant. A thermostat 20 in the refrigerator is arranged inside the freezer 18, and the operation of the compressor 14 is controlled in accordance with temperature information in the refrigerator detected by the thermometer 20. Note that a fan 22 is provided in the condenser 16, and forced air cooling is performed by rotation of the fan 22.

In the refrigerating apparatus, when the compressor 14 and the fan 22 are operated (ON) to start the refrigerating operation, the refrigerant circulated and supplied to the evaporator 12 disposed inside the freezer 18 and the internal Due to the heat exchange with the air, the internal temperature gradually decreases. When the temperature in the refrigerator decreases and the temperature falls below the set temperature of the thermo 20 in the refrigerator, the compressor 14 and the fan 22 are stopped (OFF). The temperature in the refrigerator increases with time due to heat entering from the outside of the refrigerator and the like. When the temperature in the refrigerator becomes higher than the set temperature of the thermostat 20 in the refrigerator, the compressor 14 and the fan 22 are operated (ON), and the refrigerator is frozen again. Operation is resumed. By repeating the above cycle, the internal temperature is maintained near the set temperature of the internal thermo 20.

[0004]

In the refrigerating apparatus, since the compressor 14 having a large capacity is used, the operation of the compressor 14 can lower the internal temperature of the refrigerator in a short time. For this reason, the compressor 1 is maintained in order to maintain the internal temperature near the set temperature.
In the start / stop operation in which the operation and the stop of Step 4 are repeated, FIG.
As shown in (1), the time during which the compressor 14 is operating (ON) is short, and the short operating time does not allow the lubricating oil to make a round in the refrigeration circuit. That is, the lubricating oil does not return to the compressor 14, and there is a risk of running out of oil or poor lubrication.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks inherent in the prior art, and has been proposed in order to solve the problem suitably. It is an object of the present invention to provide a refrigeration apparatus and an operation control method for the refrigeration apparatus capable of preventing occurrence of poor lubrication and lubrication.

[0006]

[MEANS FOR SOLVING THE PROBLEMS]
In order to appropriately achieve the intended purpose, the refrigeration apparatus according to the first invention of the present application includes a compressor that compresses a vaporized refrigerant, a condenser that condenses the compressed vaporized refrigerant into a liquefied refrigerant,
A refrigerating apparatus comprising: an expansion valve that expands a liquefied refrigerant coming from the condenser to be a vaporized refrigerant; and an evaporator that returns the vaporized refrigerant to a suction side of the compressor after performing a cooling action by the vaporized refrigerant. In the above, the refrigerant is branched from a refrigerant supply pipe that connects and connects the condenser and the expansion valve, and is connected to a suction pipe that connects and connects the evaporator and the compressor, and the liquefied refrigerant from the condenser is supplied to the suction side of the compressor. A capillary pipe to be bypassed, an electromagnetic valve interposed on the high pressure side of the capillary pipe, and an electromagnetic valve that is opened and closed according to a detected temperature of a thermostat in the refrigerator for detecting a temperature in the refrigerator in which the evaporator is disposed, and Temperature detecting means for detecting the refrigerant temperature on the low pressure side of the compressor and controlling the opening and closing of the expansion valve.

In order to solve the above-mentioned problems and appropriately achieve the intended purpose, a method for controlling the operation of a refrigeration apparatus according to a second aspect of the present invention includes a compressor for compressing a vaporized refrigerant and a compressor for compressing the compressed refrigerant. A condenser that condenses the vaporized refrigerant into a liquefied refrigerant, an expansion valve that expands the liquefied refrigerant arriving from the condenser and converts the vaporized refrigerant into a vaporized refrigerant, and performs a cooling operation with the vaporized refrigerant. In a refrigerating apparatus comprising an evaporator returning to the suction side of the compressor, in a state in which the compressor is continuously operated, the inside of the refrigerator is detected from a set value of a thermo in the refrigerator for detecting a temperature in the refrigerator in which the evaporator is disposed. When the temperature decreases, the solenoid valve inserted on the high pressure side of the capillary pipe branched from the refrigerant supply pipe communicating with the condenser and the expansion valve is opened to allow the liquefied refrigerant from the condenser to flow through the capillary pipe. To the suction side of the compressor When the temperature on the low pressure side of the compressor is reduced by the bypass of the liquefied refrigerant, the expansion valve is controlled to close so as to reduce the supply amount of the liquefied refrigerant to the evaporator. When the internal temperature becomes higher than the set value, the solenoid valve is closed to stop the bypass of the liquefied refrigerant, and when the low-pressure side temperature of the compressor becomes higher due to the stoppage of the bypass of the liquefied refrigerant, The expansion valve is controlled to open so as to increase the supply amount of the liquefied refrigerant to the evaporator.

[0008] In order to solve the above-mentioned problems and appropriately achieve the intended object, a refrigeration apparatus according to a third invention of the present application comprises:
A compressor that compresses the vaporized refrigerant, a condenser that condenses the compressed vaporized refrigerant into a liquefied refrigerant, and an expansion valve that expands the liquefied refrigerant coming from the condenser into a vaporized refrigerant,
After performing a cooling action by the vaporized refrigerant, in a refrigeration apparatus including an evaporator that returns the vaporized refrigerant to the suction side of the compressor, the refrigerant is branched from a refrigerant supply pipe that connects and connects the condenser and the expansion valve. A capillary pipe connected to a suction pipe that connects and connects the evaporator and the compressor, and a liquefied refrigerant from a condenser to be bypassed to a suction side of the compressor; and an electromagnetic valve inserted on a high pressure side of the capillary pipe, Controlling the operation / stop of the compressor according to the temperature detected by the thermostat in the refrigerator for detecting the temperature in the refrigerator in which the evaporator is provided, and the integrated values of the operation time and the stop time of the compressor. A control device that calculates the operating rate in accordance with the operating rate, controls the opening and closing of the solenoid valve in accordance with the operating rate, detects a refrigerant temperature on the low pressure side of the compressor, and detects temperature in the opening and closing of the expansion valve. That it consists of And butterflies.

In order to solve the above-mentioned problems and appropriately achieve the intended object, an operation control method for a refrigeration apparatus according to a fourth aspect of the present invention includes a compressor for compressing a vaporized refrigerant, and a compressor for compressing the compressed refrigerant. A condenser that condenses the vaporized refrigerant into a liquefied refrigerant, an expansion valve that expands the liquefied refrigerant arriving from the condenser and converts the vaporized refrigerant into a vaporized refrigerant, and performs a cooling operation with the vaporized refrigerant. In a refrigeration system including an evaporator returned to the suction side of the compressor, a start / stop operation in which the operation of the compressor is repeatedly started and stopped is performed to detect a temperature in a refrigerator in which the evaporator is disposed. The operation time and the stop time of the compressor during the start / stop operation are respectively integrated, and the operation rate obtained from the integrated value at the time of the stop time becomes smaller than the set value. If so, connect the compressor In the continuous operation, the capillary pipe branches from a refrigerant supply pipe communicating the condenser and the expansion valve when the internal temperature is lower than a set value of the internal thermo in the continuous operation. The solenoid valve inserted on the high-pressure side of the compressor is opened to allow the liquefied refrigerant from the condenser to bypass to the suction side of the compressor through the capillary tube, and the bypass on the liquefied refrigerant lowers the temperature on the low-pressure side of the compressor. When it becomes, while controlling the expansion valve to the closing direction to reduce the supply amount of the liquefied refrigerant to the evaporator,
When the internal temperature becomes higher than the set value of the internal thermostat, the electromagnetic valve is closed to stop the bypass of the liquefied refrigerant, and the low-pressure side temperature of the compressor is increased by stopping the bypass of the liquefied refrigerant. When this happens, the expansion valve is controlled to open so as to increase the supply amount of the liquefied refrigerant to the evaporator, and when the operation rate becomes larger than a set value, the compressor is shifted to start / stop operation. It is characterized by the following.

[0010] In order to solve the above-mentioned problems and appropriately achieve the intended object, a refrigeration apparatus according to a fifth aspect of the present invention includes:
A compressor that compresses the vaporized refrigerant, a condenser that condenses the compressed vaporized refrigerant into a liquefied refrigerant, and an expansion valve that expands the liquefied refrigerant coming from the condenser into a vaporized refrigerant,
After performing a cooling action by the vaporized refrigerant, in a refrigeration apparatus including an evaporator that returns the vaporized refrigerant to the suction side of the compressor, the refrigerant is branched from a refrigerant supply pipe that connects and connects the condenser and the expansion valve. A capillary pipe connected to a suction pipe that connects and connects the evaporator and the compressor, and a liquefied refrigerant from a condenser to be bypassed to a suction side of the compressor; and an electromagnetic valve inserted on a high pressure side of the capillary pipe, The number of counts of a counter that controls the operation and stop of the compressor according to the temperature detected by the thermostat in the refrigerator that detects the temperature in the refrigerator in which the evaporator is provided, and that counts the number of times the compressor starts and stops. And a temperature detecting means for detecting the temperature of the refrigerant on the low pressure side of the compressor and controlling the opening and closing of the expansion valve.

In order to solve the above-mentioned problems and appropriately achieve the intended object, a method for controlling the operation of a refrigeration system according to a sixth aspect of the present invention includes a compressor for compressing a vaporized refrigerant and a compressor for compressing the compressed refrigerant. A condenser that condenses the vaporized refrigerant into a liquefied refrigerant, an expansion valve that expands the liquefied refrigerant arriving from the condenser and converts the vaporized refrigerant into a vaporized refrigerant, and performs a cooling operation with the vaporized refrigerant. In a refrigeration system including an evaporator returned to the suction side of the compressor, a start / stop operation in which the operation of the compressor is repeatedly started and stopped is performed to detect a temperature in a refrigerator in which the evaporator is disposed. The number of times the compressor is started and stopped by the start / stop operation is counted, and when the count reaches the set value, the operation mode shifts to a continuous operation in which the compressor is continuously operated. And in the continuous operation, When the internal temperature becomes lower than the set value of the internal thermometer, the electromagnetic valve inserted into the high pressure side of the capillary pipe branched from the refrigerant supply pipe communicating the condenser and the expansion valve is opened to open the condenser. The liquefied refrigerant from the compressor is bypassed to the suction side of the compressor via a capillary tube, and when the temperature on the low pressure side of the compressor is reduced by the bypass of the liquefied refrigerant, the expansion valve is controlled in the closing direction to the evaporator. The supply amount of the liquefied refrigerant is reduced, and when the internal temperature becomes higher than the set value of the internal thermostat, the solenoid valve is closed to stop the bypass of the liquefied refrigerant, and the bypass of the liquefied refrigerant is stopped. When the temperature on the low pressure side of the compressor increases due to the stop, the expansion valve is controlled to open to increase the amount of liquefied refrigerant supplied to the evaporator, and the count is reset when the solenoid valve is closed. And then The internal thermo setting inside temperature than is characterized in that so as to shift to the calling stop operation when it is low.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a refrigeration apparatus and an operation control method thereof according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments.

[0013]

FIG. 1 shows a schematic configuration of a refrigeration apparatus according to a first embodiment. The basic circuit is the same as that described with reference to FIG. Therefore, the same members are designated by the same reference numerals. That is, the discharge pipe 24 led out from the discharge side of the compressor 14 is connected to the inlet side of the condenser 16, and the refrigerant supply pipe 26 led out of the condenser 16 is connected to the inside of the freezer 18 via the expansion valve 10. The evaporator 12 is connected to the inlet side of the evaporator 12. Also,
A suction pipe 28 led out from the outlet side of the evaporator 12 is connected to the suction side of the compressor 14. In the refrigeration apparatus of the first embodiment, the refrigeration apparatus using the large-capacity compressor 14 is performed by continuously operating the compressor 14 from the start to the stop of the operation of the apparatus. In this case, the compressor 14 is prevented from running out of oil and poor lubrication.

A temperature sensing cylinder 30 as temperature detecting means is disposed in close contact with a portion of the suction pipe 28 close to the compressor 14, and the temperature sensing cylinder 30 detects a low pressure side (a suction side of the compressor 14). )), The expansion valve 10
Is configured to automatically control the degree of superheat by controlling the opening and closing of the air conditioner. That is, when the temperature detected by the temperature-sensitive cylinder 30 is low, the expansion valve 10 is controlled to be closed, the amount of circulation of the liquefied refrigerant to the evaporator 12 is suppressed, and when the temperature detected by the temperature-sensitive cylinder 30 is high, The expansion valve 10 is controlled to open, and increases the amount of liquefied refrigerant circulated to the evaporator 12. A pressure equalizing pipe 32 connected to the expansion valve 10 is connected to a suction pipe 28 between the position where the temperature sensing cylinder 30 is provided and the compressor 14. This equalizing tube 32
Is connected to the outlet side of the evaporator 12 and the expansion valve 10 so as to correct a pressure drop in the evaporator 12 and function to maintain an appropriate degree of superheat.

A bypass pipe 34 branched from the refrigerant supply pipe 26 between the condenser 16 and the expansion valve 10 is connected to a suction pipe 28 via a solenoid valve 36 and a capillary pipe 38 inserted in series. (The solenoid valve 36 is connected to the high pressure side of the capillary tube 38). The solenoid valve 36 is
Opening / closing control is performed in accordance with information on the inside temperature detected by the inside thermo 20 disposed inside the freezer 18. That is, when the internal temperature F becomes lower than the preset value E (set temperature) preset in the internal thermo 20, the solenoid valve 36
Is controlled to open (ON) and close (OFF) when it becomes high (see FIG. 2). When the solenoid valve 36 is opened (ON), the liquefied refrigerant from the condenser 16 flows into the suction side (low pressure side) of the compressor 14 through the capillary tube 38,
Here, by vaporizing, the heat of vaporization is taken as in the case of the evaporator, and the compressor 14 can be cooled to prevent overheating. In addition, a check valve 40 is inserted on the evaporator side from the connection point K of the suction pipe 28 with the bypass pipe 34, and the bypass pipe 34 is connected to the suction pipe 2.
The liquefied refrigerant flowing into the evaporator 8 is prevented from flowing back to the evaporator 12.

[0016]

Next, the operation of the refrigeration system according to the first embodiment will be described with reference to the timing chart of FIG. Before the operation of the refrigerating apparatus, the expansion valve 10 has an opening degree for obtaining a preset degree of superheat, and the electromagnetic valve 36 is closed (OFF).

When the power supply (not shown) is turned on to start the operation of the refrigerating apparatus, the compressor 14 and the fan 22 operate.
(ON), and the vaporized refrigerant compressed by the compressor 14 is supplied to the condenser 1
6, the liquefied refrigerant is decompressed by the expansion valve 10, evaporates in the evaporator 12, and exchanges heat with the air in the refrigerator.
Cool the chamber. Then, the cycle in which the vaporized refrigerant returns to the compressor 14 through the suction pipe 28 is repeated.

When the internal temperature of the refrigerator gradually decreases due to the circulation of the refrigerant and the internal temperature F becomes lower than the set value E of the internal thermostat 20, the compressor 14 is continuously operated (ON) and the solenoid valve is continuously operated (ON). 36 is opened (ON), and the liquefied refrigerant from the condenser 16 flows into the low pressure side of the compressor 14 via the capillary tube 38. Since the inlet of the liquefied refrigerant is on the outlet side of the evaporator 12, there is no heat absorption, and the liquefied refrigerant flows to the expansion valve temperature-sensitive cylinder 30 in a liquefied state. Therefore, the detected temperature of the temperature-sensitive cylinder 30 becomes low, and the expansion valve 10 is controlled to close so as to adjust to the set degree of superheat. Therefore, the amount of refrigerant circulating to the evaporator 12 is reduced more than necessary, the evaporating temperature of the evaporator 12 rises, and the temperature inside the refrigerator gradually rises. By supplying the liquefied refrigerant to the compressor 14, overheating of the compressor 14 is prevented.

When the internal temperature F becomes higher than the set value E of the internal thermo 20, the solenoid valve 36 is closed (OFF), and the supply of the liquefied refrigerant to the low pressure side via the capillary pipe 38 is stopped. . As a result, the amount of refrigerant circulating through the suction pipe 28 is reduced, and the temperature detected by the temperature-sensitive cylinder 30 is increased.
0 is controlled in the opening direction. Therefore, the circulation amount of the liquefied refrigerant to the evaporator 12 increases, the evaporating temperature of the evaporator 12 decreases, and the inside of the refrigerator is gradually cooled. When the internal temperature F falls below the set value E of the internal thermo 20, the solenoid valve 3
6 is opened (ON) and the supply of the liquefied refrigerant to the low pressure side via the capillary tube 38 is started. Thereafter, the cycle is repeated, so that the internal temperature F is maintained near the set value E.

As described above, in the first embodiment, since the compressor 14 is operated continuously, the cycle of lubricating oil circulating in the refrigeration circuit together with the refrigerant and returning to the compressor 14 again is repeated. The occurrence of poor lubrication is prevented. That is, in a quick freezing storage or the like that uses a large-capacity compressor 14 with respect to the load in the refrigerator, a drawback caused by repeating the short-time operation of the compressor 14 to maintain the temperature in the refrigerator at a set value is eliminated. Can be resolved. Further, by causing the liquefied refrigerant to flow to the low pressure side through the capillary tube 38, it is possible to suppress the temperature rise of each component of the compressor 14 and the lubricating oil, and to prevent the deterioration of the lubricating oil. Further, the temperature of the vaporized refrigerant discharged from the compressor 14 can be reduced.

[0021]

Second Embodiment FIG. 3 shows a schematic configuration of a refrigeration apparatus according to a second embodiment. The basic circuit is the same as that of the first embodiment, and only different portions will be described.

That is, the refrigeration system includes a control device 42 for controlling the opening and closing of the solenoid valve 36. The control device 42 integrates the operation time (ON time) and the stop time (OFF time) of the compressor 14, and each time the stop time (OFF time) is added, the operation rate is calculated by the integrated value. Is calculated. The operating rate is the integrated value of the operating time:
When X (second), the integrated value of the stop time: Y (second), and the operation rate: T (%), it can be obtained by the following equation. T = (X / (X + Y)) × 100 When the operation rate T is larger than the set value U (for example, 30%), the inside temperature control by the start / stop operation in which the operation and the stop of the compressor 14 are repeated is performed. If the set value U is smaller than the set value U, the internal temperature control is performed in the continuous operation for continuously operating the compressor 14 described in the first embodiment.

In the refrigerating apparatus of the second embodiment, the temperature information of the thermostat 20 in the refrigerator is inputted to the control device 42, and the operation / stop of the compressor 14 is controlled based on the temperature information. ing. That is, the compressor 14 is controlled so as to stop (OFF) when the in-compartment temperature F becomes lower than a preset value E preset in the in-compartment thermostat 20, and to operate (ON) when it becomes higher. Further, the evaporator 12 is provided with a defrosting thermometer 44 for detecting the end of the defrosting operation periodically performed by a timer or the like, and based on the detection of the defrosting end of the thermostat 44, the control device 42 The integrated values X and Y are set to be reset to “0”, respectively.

[0024]

Next, the operation of the refrigeration system according to the second embodiment will be described with reference to the timing chart of FIG. 4 and the flowchart of FIG. Before the operation of the refrigeration system, the expansion valve 10
Is an opening for obtaining a preset degree of superheat, and the solenoid valve 36 is closed (OFF).

As shown in the flowchart of FIG. 5, when the operation of the refrigerating apparatus is started in step S1, step S1 is started.
After the compressor 14 is operated (ON) in step 2, the compressor start / stop number N, the integrated value X of the operating time, and the integrated value Y of the stop time are reset to "0" in step S3. When the compressor 14 is operated (ON), the liquefied refrigerant compressed by the compressor 14 is liquefied in the condenser 16, and the liquefied refrigerant is decompressed by the expansion valve 10 and evaporated in the evaporator 12. It exchanges heat with the air inside the refrigerator to cool the refrigerator. Then, the cycle of returning the evaporated and vaporized refrigerant to the compressor 14 via the suction pipe 28 is repeated, so that the internal temperature F gradually decreases.

When the internal temperature F becomes lower than the set value E of the internal thermo 20, the compressor 14 is stopped in step S 4.
(OFF) and accumulates the operation time. Compressor 1
Since the refrigerant is not circulated to the evaporator 12 due to the stop (OFF) of Step 4, the temperature inside the refrigerator rises with time due to heat entering from outside the refrigerator and the like, and the temperature F inside the refrigerator becomes the set value E of the thermo 20 inside the refrigerator.
If it becomes higher, the compressor 14 operates (O) in step S5.
N), and the circulation of the refrigerant is started again. In step S5, the stop time of the compressor 14 is integrated.

Next, in step S6, the number of compressor start / stop times N is compared. If N <1, the process proceeds to step S7, where the integrated value X of the operating time and the integrated value Y of the stop time are each set to "0". After adding “1” to the compressor start / stop number N (step S8), the process returns to step S4. Step S6
When it is determined that N ≧ 1, the process proceeds to step S9,
The operation rate T is calculated based on the integrated value X of the operating time and the integrated value Y of the stop time.
Is calculated. Next, in step S10, it is checked whether or not defrosting is being performed. If the result is affirmative (YES), the process returns to step S3. Reset to "0" and repeat the flow described above. If the result of the determination in step S10 is negative (NO), the process proceeds to step S11, where the operation rate T is compared with the set value U. If T> U, the compressor start / stop number N is set to "N" in step S8. After adding "1", the process returns to step S4, and the flow of the start / stop operation of the compressor 14 described above is repeated.

If T <U in step S11, the operation shifts to a continuous operation in which the compressor 14 is continuously operated. That is, while the compressor 14 is operated (ON), step S1 is performed.
In step 2, the solenoid valve 36 is opened (ON), the liquefied refrigerant from the condenser 16 is bypassed to the suction side of the compressor 14 via the capillary tube 38, and the internal cooling of the evaporator 12 is suppressed. After confirming that the inside temperature F has become higher than the set value E in step S13, the solenoid valve 36 is closed (OFF) in step 14, and the inside cooling in the evaporator 12 is restarted.
When the internal temperature F cooled by the continuous operation becomes lower than the set value E of the internal thermo 20 again, "1" is added to the compressor start / stop number N in step S8, and the process returns to step S4. Then, the flow shifts to the flow of the start / stop operation of the compressor 14 described above.

As described above, in the second embodiment, the compressor 1
4, the compressor 14 is periodically switched from the start / stop operation to the continuous operation, so that during the continuous operation, the lubricating oil circulates in the refrigeration circuit together with the refrigerant and returns to the compressor 1 again.
4, the oil shortage and poor lubrication can be prevented beforehand.
That is, in a quick freezing storage or the like using a compressor 14 having a large capacity with respect to the load in the refrigerator, the lubricating oil circulates while the compressor 14 is repeatedly operated for a short time in order to maintain the temperature in the refrigerator at a set value. By performing such a continuous operation, it is possible to prevent oil shortage and poor lubrication from occurring. Also,
When the solenoid valve 36 is opened (ON) during the continuous operation, the liquefied refrigerant flows into the low-pressure side through the capillary tube 38, so that the temperature rise of each component of the compressor 14 and the lubricating oil is suppressed, and the deterioration of the lubricating oil is suppressed. Can be prevented. Further, the compressor 14
It is also possible to lower the temperature of the vaporized refrigerant discharged from the heater. Normally, the internal temperature is controlled by the start / stop operation of the compressor 14, so that the power consumption can be suppressed during the operation of the refrigeration apparatus as compared with the control of continuously operating the compressor 14 as in the first embodiment. it can.

[0030]

Third Embodiment FIG. 6 shows a schematic configuration of a refrigerating apparatus according to a third embodiment. Since the basic circuit is the same as that of the second embodiment, only different portions will be described.

That is, the refrigeration system has a control device 46 for controlling the opening and closing of the solenoid valve 36. The control device 46 includes a counter 48 that counts the number of times the compressor 14 starts and stops, and the count number G is set to a set value H (for example, 4
Until the compressor 14 is operated, the internal temperature control is performed by a start / stop operation for operating / stopping the compressor 14. When the set value H is reached, the compressor 14 is operated continuously as described in the first embodiment. Is controlled to perform the inside temperature control. Compressor 1
After the shift to the continuous operation, the solenoid valve 36 is closed.
(OFF), the control device 46 resets the count number G, and then returns the compressor 14 to the start / stop operation when the internal temperature F becomes lower than the set value E of the internal thermo 20 next time. Control is performed.

[0032]

Next, the operation of the refrigeration system according to the third embodiment will be described with reference to the timing chart of FIG. 7 and the flowchart of FIG. Before the operation of the refrigeration system, the expansion valve 10
Is an opening for obtaining a preset degree of superheat, and the solenoid valve 36 is closed (OFF). Also, it is assumed that the set value H of the number of start / stop times of the compressor 14 is set to “4”.

As shown in the flowchart of FIG. 8, when the operation of the refrigerating apparatus is started in step S20, first, in step 21, the set value E of the thermostat 20 in the refrigerator and the temperature F in the refrigerator are compared. At this time, since the internal temperature F is higher than the set value E, it is determined in step 21 that E <F, and step S2
The process proceeds to step S2, where the count value G of the number of start / stop times of the compressor 14 is compared with the set value H. Since the count number G is “0”,
In step 22, it is determined that G <H, and the process proceeds to step S23, where the compressor 14 is operated (ON) and the count number G is set.
Then, the process returns to step S21.

When the compressor 14 is operated (ON) as described above, the liquefied refrigerant compressed by the compressor 14 is
The liquefied refrigerant is decompressed by the expansion valve 10 and evaporates in the evaporator 12 to exchange heat with the air in the refrigerator, thereby cooling the refrigerator. Then, the vaporized refrigerant is supplied to the suction pipe 2
By repeating the cycle of returning to the compressor 14 via 8, the internal temperature rapidly decreases. And in-chamber thermo 2
When the internal temperature F becomes lower than the set value E of 0, the step S
At 21 it is determined that E ≧ F, and the process proceeds to step S24 to compare the count G of the number of times of starting and stopping of the compressor 14 with the set value H. Since the count number G at this time is "1", it is determined that G <H in step S24, the compressor 14 is stopped (ON) in step S25, and then the process returns to step S21.

Since the refrigerant is not circulated to the evaporator 12 when the compressor 14 is stopped (OFF), the internal temperature F rises with the passage of time due to heat entering from the outside and the like, and the internal temperature F
Is higher than the set value E of the thermostat 20 in the refrigerator, it is determined that E <F in step S21, and the process proceeds to step S22 to compare the count G of the number of times of start / stop of the compressor 14 with the set value H. Until the count number G becomes equal to the set value H, the temperature inside the refrigerator is controlled by the start / stop operation in which the operation and the stop of the compressor 14 described above are repeated.

In step S23, the count G is "4".
Then, in the state where the compressor 14 is operating (ON), it is determined in step 21 that the internal temperature F has become lower than the set value E of the internal thermo 20 (E ≧ F). Then, the process proceeds to step S24, where it is determined that G ≧ H. Therefore, in this case, the solenoid valve 36 is opened (ON) in step S26.
The liquefied refrigerant from the condenser 16 is supplied to the capillary tube 38.
To the suction side of the compressor 14 through the evaporator 1
The internal cooling in step 2 is suppressed, and the process returns to step S21.

In the continuous operation of the compressor 14, the internal temperature F became higher than the set value E in step S21 (E
If the determination is <F), the count value G of the number of times of starting and stopping of the compressor 14 is compared with the set value H in step S22. At this time, since the count number G is "4", the process shifts to step S27 to close (OFF) the electromagnetic valve 36 and restart the internal cooling in the evaporator 12. Further, after resetting the count G of the number of times of starting and stopping of the compressor 14 to “0”, the process returns to step S21. Then, when the internal temperature F cooled in the continuous operation becomes lower than the set value E of the internal thermo 20 again, it is determined that E ≧ F in step S21, and the process proceeds to step S24. As described above, since the count number G has been reset to "0", it is determined that G <H in step S24, the compressor 14 is stopped (OFF) in step S25, and the process returns to step S21. Until the number G becomes "4" again, the internal temperature control by the start / stop operation of the compressor 14 is performed.

As described above, in the third embodiment, the compressor 1
4 based on the count G of the number of start / stop times of the compressor 14.
Is periodically switched from the start / stop operation to the continuous operation, and during the continuous operation, the lubricating oil circulates in the refrigeration circuit together with the refrigerant and returns to the compressor 14 again, so that it is possible to prevent oil shortage and poor lubrication. That is, in a quick freezing storage or the like using a compressor 14 having a large capacity with respect to the load in the refrigerator, the lubricating oil circulates while the compressor 14 is repeatedly operated for a short time in order to maintain the temperature in the refrigerator at a set value. By performing such a continuous operation, it is possible to prevent oil shortage and poor lubrication from occurring. Also, open the solenoid valve 36 during continuous operation
When (ON), the liquefied refrigerant flows into the low pressure side via the capillary tube 38, so that the temperature rise of each component of the compressor 14 and the lubricating oil can be suppressed, and deterioration of the lubricating oil can be prevented.
Further, the temperature of the vaporized refrigerant discharged from the compressor 14 can be reduced. Normally, the internal temperature is controlled by the start / stop operation of the compressor 14, so that the power consumption can be suppressed during the operation of the refrigeration apparatus as compared with the control of continuously operating the compressor 14 as in the first embodiment. it can.

[0039]

As described above, according to the refrigerating apparatus and the operation control method thereof according to the present invention, the internal temperature can be maintained near the set value while the compressor is continuously operated.
The lubricating oil always circulates in the refrigeration circuit together with the refrigerant, and can prevent running out of oil and poor lubrication. In addition, by causing the liquefied refrigerant to flow into the low-pressure side of the compressor via the capillary tube, it is possible to suppress a rise in the temperature of each component of the compressor and the lubricating oil, thereby preventing deterioration of the lubricating oil. Further, the temperature of the vaporized refrigerant discharged from the compressor can be reduced.

Also, by periodically switching the compressor from the start / stop operation to the continuous operation based on the operation rate of the compressor and the number of start / stop operations, the lubricating oil circulates in the refrigeration circuit together with the refrigerant during the continuous operation. Then, since the compressor returns to the compressor again, running out of oil and poor lubrication can be prevented. When the solenoid valve is opened during continuous operation, the liquefied refrigerant flowing into the low-pressure side through the capillary pipe suppresses the temperature rise of each component of the compressor and the lubricating oil, thereby preventing deterioration of the lubricating oil. The temperature of the vaporized refrigerant discharged from the compressor can be reduced. Furthermore, normally, the continuous operation is periodically performed under the control of the internal temperature of the refrigerator by the start / stop operation of the compressor. Power can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a timing chart during operation of the refrigeration apparatus according to the first embodiment.

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

FIG. 4 is a timing chart of the operation of the refrigeration apparatus according to the second embodiment.

FIG. 5 is a flowchart when the refrigeration apparatus according to the second embodiment operates.

FIG. 6 is a schematic configuration diagram illustrating a refrigeration apparatus according to a third embodiment of the present invention.

FIG. 7 is a timing chart of the operation of the refrigeration apparatus according to the third embodiment.

FIG. 8 is a flowchart of the operation of the refrigeration apparatus according to the third embodiment.

FIG. 9 is a schematic configuration diagram showing a refrigeration apparatus according to a conventional technique.

FIG. 10 is a timing chart when a refrigeration apparatus according to a conventional technique is operated.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Expansion valve, 12 Evaporator, 14 Compressor, 16 Condenser, 20 Internal thermostat 26 Refrigerant supply pipe, 28 Suction pipe,
Reference Signs List 30 temperature sensing cylinder (temperature detecting means), 36 solenoid valve 38 capillary tube, 40 check valve, 42 control device, 46
Control device 48 counter, E setting value of thermo in the refrigerator, F
Internal temperature, G count number H Set value of count number, K
Connection point, set value of T operation rate, U operation rate X Integrated value of operating time, Y Integrated value of stop time

Claims (7)

[Claims] A compressor (14) for compressing a vaporized refrigerant, and a condenser (1) for condensing the compressed vaporized refrigerant into a liquefied refrigerant.
6), an expansion valve (10) that expands the liquefied refrigerant arriving from the condenser (16) and converts the liquefied refrigerant into a vaporized refrigerant. The evaporator (12) returns to the suction side of the evaporator (12), and branches off from the refrigerant supply pipe (26) that connects the condenser (16) and the expansion valve (10) in communication. A capillary pipe (38) connected to a suction pipe (28) that connects the compressor (14) and the compressor (14) to bypass the liquefied refrigerant from the condenser (16) to the suction side of the compressor (14); A thermostat (2) that is inserted on the high pressure side of the capillary tube (38) and detects the temperature inside the refrigerator where the evaporator (12) is disposed
(0), an electromagnetic valve (36) that is controlled to open and close in accordance with the detected temperature, and a temperature detecting means () that detects a low-pressure side refrigerant temperature of the compressor (14) and controls opening and closing of the expansion valve (10). 30) A refrigeration system characterized by comprising: 2. A compressor (14) for compressing a vaporized refrigerant, and a condenser (1) for condensing the compressed vaporized refrigerant into a liquefied refrigerant.
6), an expansion valve (10) that expands the liquefied refrigerant arriving from the condenser (16) and converts the liquefied refrigerant into a vaporized refrigerant. ), The evaporator (12) returning to the suction side of the evaporator (1) in a state where the compressor (14) is continuously operated.
In-chamber thermo (20) that detects the in-chamber temperature (F) where 2) is installed
When the internal temperature (F) becomes lower than the set value (E), the capillary pipe (38) branched from the refrigerant supply pipe (26) communicating the condenser (16) and the expansion valve (10). The liquefied refrigerant from the condenser (16) is opened to bypass the liquefied refrigerant from the condenser (16) to the suction side of the compressor (14) through the capillary tube (38), and the liquefied refrigerant is opened. When the low-pressure side temperature of the compressor (14) becomes low due to the bypass, the supply amount of the liquefied refrigerant to the evaporator (12) is reduced by controlling the expansion valve (10) in the closing direction, When the internal temperature (F) becomes higher than the set value (E) of the internal thermo (20), the solenoid valve (36) is closed to stop the bypass of the liquefied refrigerant, and the bypass of the liquefied refrigerant is stopped. When the temperature on the low pressure side of the compressor (14) increases due to the stop, the expansion valve (10) is controlled to open so as to increase the supply amount of the liquefied refrigerant to the evaporator (12). Specially An operation control method for a refrigeration system. 3. A compressor (14) for compressing a vaporized refrigerant, and a condenser (1) for condensing the compressed vaporized refrigerant into a liquefied refrigerant.
6), an expansion valve (10) that expands the liquefied refrigerant arriving from the condenser (16) and converts the liquefied refrigerant into a vaporized refrigerant. The evaporator (12) returns to the suction side of the evaporator (12), and branches off from the refrigerant supply pipe (26) that connects the condenser (16) and the expansion valve (10) in communication. A capillary pipe (38) connected to a suction pipe (28) that connects the compressor (14) and the compressor (14) to bypass the liquefied refrigerant from the condenser (16) to the suction side of the compressor (14); The solenoid valve (3) inserted on the high pressure side of the capillary tube (38)
6), the operation of the compressor (14) according to the temperature detected by the in-chamber thermo (20) for detecting the temperature in the chamber in which the evaporator (12) is disposed.
In addition to controlling the stop, the operation rate (T) is calculated based on the integrated value (X, Y) of the operation time and the stop time of the compressor (14), and the solenoid valve is operated according to the operation rate (T). A control device (42) for controlling the opening and closing of the (36), and a temperature detecting means (30) for detecting the low-pressure side refrigerant temperature of the compressor (14) and controlling the opening and closing of the expansion valve (10). A refrigeration apparatus characterized by comprising. 4. A compressor (14) for compressing a vaporized refrigerant, and a condenser (1) for condensing the compressed vaporized refrigerant into a liquefied refrigerant.
6), an expansion valve (10) that expands the liquefied refrigerant arriving from the condenser (16) and converts the liquefied refrigerant into a vaporized refrigerant. ), The evaporator (12) returning to the suction side of the compressor (14). Temperature (F)
The temperature (F) is maintained at the set value (E) of the in-compartment thermometer (20) for detecting the temperature (F), and the operation time and the stop time of the compressor (14) due to the start / stop operation are respectively integrated, and the stop time is calculated. When the operation rate (T) obtained from the integrated value (X, Y) at the time of integration becomes smaller than the set value (U), the operation shifts to the continuous operation in which the compressor (14) is continuously operated, and the continuous operation is performed. In the setting value of the thermo in the refrigerator (20)
When the internal temperature (F) becomes lower than (E), the condenser (1
An electromagnetic valve (36) inserted on the high pressure side of a capillary tube (38) branching from a refrigerant supply tube (26) communicating the expansion valve (6) with the expansion valve (10).
And release the liquefied refrigerant from the condenser (16) to the capillary tube.
When the temperature on the low-pressure side of the compressor (14) is reduced by the bypass of the liquefied refrigerant, the expansion valve (10) is controlled to be closed. And the supply amount of the liquefied refrigerant to the evaporator (12), and when the internal temperature (F) becomes higher than the set value (E) of the internal thermo (20), the electromagnetic valve ( 36) to stop the bypass of the liquefied refrigerant, and control the expansion valve (10) to open when the low pressure side temperature of the compressor (14) becomes higher due to the stoppage of the liquefied refrigerant bypass. The supply amount of the liquefied refrigerant to the evaporator (12) is increased, and when the operation rate (T) becomes larger than a set value (U), the compressor (14) is shifted to a start / stop operation. An operation control method for a refrigeration apparatus, comprising: 5. A compressor (14) for compressing a vaporized refrigerant, and a condenser (1) for condensing the compressed vaporized refrigerant into a liquefied refrigerant.
6), an expansion valve (10) that expands the liquefied refrigerant arriving from the condenser (16) and converts the liquefied refrigerant into a vaporized refrigerant. The evaporator (12) returns to the suction side of the evaporator (12), and branches off from the refrigerant supply pipe (26) that connects the condenser (16) and the expansion valve (10) in communication. A capillary pipe (38) connected to a suction pipe (28) that connects the compressor (14) and the compressor (14) to bypass the liquefied refrigerant from the condenser (16) to the suction side of the compressor (14); The solenoid valve (3) inserted on the high pressure side of the capillary tube (38)
6), the operation of the compressor (14) according to the temperature detected by the in-chamber thermo (20) for detecting the temperature in the chamber in which the evaporator (12) is disposed.
A control device (46) for controlling the stop and controlling the opening and closing of the solenoid valve (36) according to the count (G) of a counter (48) for counting the number of times the compressor (14) starts and stops; A refrigeration system comprising: a temperature detecting means (30) for detecting a refrigerant temperature on a low pressure side of the compressor (14) and controlling opening and closing of the expansion valve (10). 6. A compressor (14) for compressing a vaporized refrigerant, and a condenser (1) for condensing the compressed vaporized refrigerant into a liquefied refrigerant.
6), an expansion valve (10) that expands the liquefied refrigerant arriving from the condenser (16) and converts the liquefied refrigerant into a vaporized refrigerant. ), The evaporator (12) returning to the suction side of the compressor (14). Temperature (F)
The temperature (F) is kept at the set value (E) of the thermostat (20) for detecting the temperature, and the number of start / stop of the compressor (14) by the start / stop operation is counted. When the set value (H) is reached, the operation shifts to a continuous operation in which the compressor (14) is continuously operated.In the continuous operation, the set value of the in-chamber thermo (20) is set.
When the internal temperature (F) becomes lower than (E), the condenser (1
An electromagnetic valve (36) inserted on the high pressure side of a capillary tube (38) branching from a refrigerant supply tube (26) communicating the expansion valve (6) with the expansion valve (10).
And release the liquefied refrigerant from the condenser (16) to the capillary tube.
When the temperature on the low-pressure side of the compressor (14) is reduced by the bypass of the liquefied refrigerant, the expansion valve (10) is controlled to be closed. And the supply amount of the liquefied refrigerant to the evaporator (12), and when the internal temperature (F) becomes higher than the set value (E) of the internal thermo (20), the electromagnetic valve ( 36) is closed to stop the bypass of the liquefied refrigerant, and when the low pressure side temperature of the compressor (14) becomes higher due to the stoppage of the liquefied refrigerant bypass, the expansion valve (36) is controlled to open. The supply amount of the liquefied refrigerant to the evaporator (12) is increased, the count number (G) is reset when the solenoid valve (36) is closed, and then the set value (E ) Than internal temperature
An operation control method for a refrigeration system, wherein the operation shifts to the start / stop operation when (F) becomes low. 7. A check valve (40) is inserted in the suction pipe (28) on the evaporator side from the connection point (K) between the capillary pipe (38) and the suction pipe (28). The refrigeration apparatus according to any of 3 or 5.