JPH10185334A - Refrigerating equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start refrigerating equipment from a stopped state smoothly and quickly. SOLUTION: The capacity of a compressor 3 of refrigerating equipment 1 can be controlled in a plurality of steps by an unload device 7. At the time of starting the compressor 3 from a state of stop of operation, a control means 10 repeats an extremely low step wherein a refrigerating capacity is not present nearly at all and the lowest step at the time of an ordinary operation, for a prescribed time set by a timer 11 and in a prescribed number of times set in a counter 12. Thereby a refrigerant collected in a water-side heat exchanger 2 operating as an evaporator during the stop of operation can be transferred to an air-side heat exchanger operating as a condenser, without causing liquid compression and quickly. The number of times of repetition is increased when the period of the stop of operation is judged to be of a long time or when the frequency of the start and the stop is judged to be large, by a long time detecting means 22 or a storage means 23. Besides, a solenoid valve 20 for opening and closing an expansion valve is operated and thereby a pump-down operation is also conducted in parallel at the time of the start.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system having a compressor having an extremely low step and capable of controlling the capacity, and more particularly to a refrigeration system capable of operating smoothly at startup.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Publication No.
No. 8 discloses a compressor having a very low step capacity, which is capable of controlling the capacity in a plurality of load steps during normal operation and having a smaller refrigerating capacity than the lowest step during normal operation and almost incapable of starting. Thus, a technique for avoiding thermo-off during normal operation is disclosed. When the refrigerating apparatus starts operating after stopping the operation, the refrigerant is in a liquid state inside the compressor or the evaporator, and if the refrigerant is rapidly compressed, the compressor may be damaged. For this reason, after operating at the extremely low step first, the compressor is operated at the further minimum step, and the operation by the normal capacity control is started after a state in which the stored refrigerant can be sufficiently circulated unevenly is started. I have.

[0003]

When the refrigeration system is started,
Even if normal operation is performed after the compressor is operated in the extremely low step, in a state where a large amount of liquid refrigerant is accumulated in the evaporator, it is not possible to sufficiently suck in the extremely low step,
In some cases, the liquid refrigerant remains until the normal operation is started, and the liquid refrigerant is sucked into the compressor to cause liquid compression. In order to prevent such liquid compression, it is necessary to make the operation time in the extremely low step sufficiently long.

When the refrigeration system is a chiller for supplying chilled water and controls to keep the temperature of the chilled water at a set temperature, the refrigeration is performed even at the lowest step during normal operation under a condition where the outside air temperature is low. There is a possibility that the capacity becomes excessive, the thermo-off state is set in a short time after the start of the normal operation, and the normal operation is repeated from the start-up operation, so that the frequency of starting and stopping is increased and the life of the compressor and the like is shortened. In such a case,
In order to reduce the frequency of starting and stopping, it is necessary to increase the amount of cold water, which increases the facility load on the user side of the refrigeration apparatus for increasing the amount of water.

It is an object of the present invention to provide a refrigeration apparatus which can smoothly and efficiently start up from an operation stop state and can reduce the amount of water retained even in a facility for supplying chilled water. .

[0006]

SUMMARY OF THE INVENTION The present invention provides a compressor (3) capable of controlling the capacity in a plurality of stages including an extremely low step having almost no refrigeration capacity and a minimum step having the lowest refrigeration capacity in a normal operation range. In the refrigerating apparatus (1) provided with
A timer (11) for measuring the operation time of the compressor (3);
A counter (12) in which a predetermined number of times is set, and a compressor (3) being set to an extremely low step for a predetermined time counted by a timer (11) at the time of start-up from an operation stop state or at the start and end of defrost operation. And a state in which the compressor (3) is operated at the minimum step for a predetermined time measured by the timer (11) until the number set in the counter (12) is reached. And a control means (10) for controlling the compressor (3) to operate in a normal operation range. According to the present invention, the control device (1
0) is a state in which the compressor (3) is operated for a predetermined time in an extremely low step and a state in which the compressor (3) is operated for a predetermined time in a minimum step when the refrigeration system (1) is started or when defrost operation is started and ended. Control is performed such that normal operation is performed after the operation is repeated a predetermined number of times. Since the operation at the minimum step is also performed for a predetermined time, the refrigerant accumulated in the evaporator or the like is also quickly sucked, and the operation time at the minimum step is limited, so that the occurrence of liquid compression or the like can be avoided. . In the start-up operation, by performing the operation of the minimum step at predetermined time intervals, the circulation of the refrigerant and the accompanying lubricating oil can be ensured, and a smooth transition to the normal operation can be made possible.

The present invention further comprises a long-time detecting means (22) for detecting whether or not a long time equal to or longer than a predetermined time has elapsed after the operation of the compressor (3) is stopped, and the control means (10). ) Refers to the long-time detection means (22),
When a long time elapses after the operation of the compressor (3) is stopped, the number of repetitions of the start-up operation is increased. According to the present invention, when a long time has elapsed after the operation of the compressor (3) is stopped, the control means (10)
Since the number of repetitions of the start-up operation is increased, the liquid refrigerant accumulated in the evaporator or the like can be reliably sucked and circulated.

The present invention further comprises storage means (23) for storing the start / stop state of the operation and stop of the compressor (3),
The control means (10) refers to the storage means (23) and increases the number of repetitions of the start-up operation when the number of start / stop of the compressor (3) within a predetermined time is larger than a predetermined reference. It is characterized by making it. According to the present invention,
When the number of times of starting and stopping of the compressor (3) within the predetermined time is larger than the reference, it means that the refrigerating capacity of the normal operation is too large. Since the control means (10) increases the number of repetitions of the start-up operation, the operation time of the compressor (3) in a state where the refrigerating capacity is reduced with an extremely low step becomes longer, and the compressor (3) is turned off. And the frequency of stoppage can be reduced.

The present invention further includes an expansion valve (6) capable of opening and closing control, wherein the control means (10) opens and closes the expansion valve (6) while repeating the extremely low step and the minimum step in the starting operation. Control is also performed repeatedly. According to the present invention, when the expansion valve (6) is closed, the refrigerant does not flow to the evaporator. Therefore, the refrigerant is prevented from flowing into the evaporator at one time and further flowing to the compressor (3). Liquid compression of the compressor (3) can be prevented. On the other hand, by repeatedly opening and closing the expansion valve (6), an appropriate amount of lubricating oil returns to the compressor (3).
Can be sufficiently lubricated.

In the present invention, the expansion valve (6) is an external pressure equalizing type temperature-sensitive expansion valve (6), and is provided between the high pressure side of the expansion valve (6) and the pressure equalizing pipe (26). Solenoid valve (2
0), and a capillary (21) provided between the pressure equalizing pipe (26) and the suction side of the compressor (3), and the control means (10) controls the compressor in accordance with the start-up operation. The solenoid valve (20) is opened to close the expansion valve (6) so that the pressure on the suction side of (3) is within a predetermined range,
The electromagnetic valve (20) is closed to control the expansion valve (6) to open. According to the present invention, the control means (10) opens and closes the solenoid valve (20) in accordance with the start-up operation, and controls the pressure equalizing pipe (2) of the external pressure equalizing type temperature-sensitive expansion valve (6).
The pressure applied to 6) can be controlled. To open the expansion valve (6), the solenoid valve (20) is closed and the refrigerant in the pressure equalizing pipe (26) is sucked into the compressor (3) through the capillary (21) to reduce the pressure. And expansion valve (6)
To close the valve, the solenoid valve (20) is opened,
Control for increasing the pressure inside the pressure equalizing pipe (26) is performed. Prevents liquid compression due to sudden suction of liquid refrigerant into the compressor (3),
The refrigerant and the lubricating oil can be smoothly transferred. It is also possible to prevent the suction pressure of the compressor from dropping to an extremely low pressure that may cause damage.

[0011]

FIG. 1 shows a schematic piping system of a refrigeration system (1) according to an embodiment of the present invention and an electrical configuration for control. The refrigeration system (1) evaporates the refrigerant at a low pressure formed by suctioning the refrigerant with a compressor (3) in a water-side heat exchanger (2), and cools the chilled water sent from a chilled water pump (4). Supply to the user side. The refrigerant evaporating in the water-side heat exchanger (2) is liquefied by condensing the refrigerant discharged from the compressor (3) using the air-side heat exchanger (5) as a condenser. When passing, the pressure is rapidly reduced and supplied.

The capacity of the compressor (3) is switched in a plurality of stages by an unloading device (7). Compressor (3)
For example, the device can be operated at a capacity of 100%, 70%, and 40% in a normal use area, and can be operated at an extremely low step of about 10% of a capacity smaller than the minimum step of 40%. In the operation at the extremely low step, the refrigeration system (1) hardly generates a refrigeration capacity.

The water-side heat exchanger (2) functions as an evaporator when the refrigerating device (1) is in a freezing operation, and when the refrigerating device (1) is performing the operation of heating the cold water by the heat pump, the condenser (1). Works as Water sent from the cold water pump (4) is introduced into the water-side heat exchanger (2) from the cold / hot water inlet (8), discharged from the cold / hot water outlet (9), and supplied to the load side. The control means (10) for controlling the temperature of the chilled water uses a timer (11) and a counter (12) to start operation when the compressor (3) shifts from a stopped state to a normal operation in accordance with a preset program. Process is also controlled. During normal operation, cold / hot water inlet (8) and cold / hot water outlet (9)
The temperature of the cold water is controlled in accordance with a predetermined operation mode such as an inlet temperature control, an outlet temperature control, or a variable water amount control with reference to the detected temperatures of the inlet-side temperature detector (13) and the outlet-side temperature detector (14). Do. Outside air temperature detector (1
5) detects the outside air temperature around the refrigeration system (1).

The expansion valve (6) is an external pressure equalizing type temperature-sensitive type, and a pipe line in which a capillary (16) and a solenoid valve (17) are connected in series is connected in parallel between a high pressure side and a low pressure side. Connected to. Further, a fan (18) for ventilating the air-side heat exchanger (5) and a chilled water tank (19) for storing chilled water for the chilled water pump (4) are also provided. Further, the pressure equalizing pipe (26) of the expansion valve (6) has a solenoid valve (20) for pumping down between the high pressure side of the expansion valve (6) and a capillary (26) between the suction side of the compressor (3). 21) are connected. The control means (10) includes:
After the compressor (3) is stopped due to thermo-off or the like, a long time detecting means (22) for detecting whether or not a stop time until start-up is, for example, two hours or more, and a storage of past start / stop. A storage means (23) is also connected. Further, the pressure on the discharge side and the pressure on the suction side of the compressor (3) are detected by a high pressure detector (24) and a low pressure detector (25), respectively.

FIG. 2 shows an operation state of each device of the refrigeration system (1) of FIG. FIG. 3 shows the operation of the control means (10) when performing control as shown in FIG. Step a1 in FIG.
The operation starts from step a2, and in step a2, the counter (12)
Is set to 3, which is the number of repetitions of the start-up operation. In step a3, it is determined whether or not the stop time is 2 hours or more by referring to the long time detecting means (22). If it is determined that the vehicle has not stopped for two hours or more, the storage unit (23) is referred to in step a4, and the start / stop cycle is short, for example, the time from the start three times ago to the start of the current start. Is less than 40 minutes. When the condition of step a3 or step a4 is satisfied, the set value of the counter (12) is increased by, for example, 2 to 5 in step a5.

When the condition is not satisfied in step a4 or when step a5 is completed, the fan (18) is started in step a6. When the fan (18) is started, for example, for 3 seconds, in step a7, the compressor (3) is turned on by about 10%.
Driving at very low steps. Timer (11) has
For example, 30 seconds are set, and after the elapse of 30 seconds, the compressor (3) is operated by increasing the capacity of the compressor (3) to the minimum step of 40% in step a8. Also at this time, the timer (11)
Is set to, for example, 30 seconds, and when 30 seconds have elapsed, the count value of the counter (12) is decreased by 1 in step a9. At step a10, the count value of the counter (12) is 0.
It is determined whether or not it is. If not, the process returns to step a7. When the condition of step a3 or step a4 is not satisfied, the operation from step a7 to step a10 is repeated three times. When the set value of the counter is increased to 5 in step a5, the number of repetitions is 5.

When the count value of the counter (12) becomes 0 in step a10, the minimum step operation is continued for another 2 minutes in step a11, and thereafter, the process proceeds to the normal control in step a12. In the starting operation up to step all,
The water temperature at the cold / hot water outlet (9) detected by the outlet-side temperature detector (14) is set to prevent freezing, for example, 3
Unless the temperature is below the freezing prevention temperature of ° C. or the fan (18) stops, the compressor (3) continues to operate even when the thermo-off condition is reached. Step a12
When the process shifts to the normal control, the normal temperature control is performed including the case where the thermostat is turned off. In the present embodiment, since the control can be quickly and smoothly shifted to the normal control, the cold water can be supplied at a stable water temperature even if the capacity of the cold water tank (19) is small.

The extremely low step is an operation state with a very low capacity, and since the compressor (3) has almost no suction capacity, it does not absorb the liquid refrigerant, but does not absorb the lubricating oil. Since there is almost no compression capacity, the refrigeration capacity of the refrigeration system is hardly exhibited. On the other hand, the compressor (3) is capable of discharging the refrigerant and the like in the compressor (3), so that a small amount of liquid refrigerant can be discharged from the compressor (3).

Therefore, even if liquid refrigerant is present on the suction side,
Although there is no danger of sucking this and causing liquid compression,
If the operation is continued for a long time, the lubricating oil does not return to the compressor (3) from the suction side, which causes seizure of the compressor (3).

The lowest step is an operation state with a small capacity having a suction capacity, albeit small, and exerts the refrigeration capacity of the refrigeration apparatus although it is small. If there is liquid refrigerant or lubricating oil on the suction side, it can be sucked.

Therefore, even if the operation is continued for a long time, the lubricating oil does not become insufficient, but if there is a liquid refrigerant on the suction side, a large amount of the liquid refrigerant may be sucked to cause liquid compression.

Therefore, if both steps are alternately operated for a short time, the invention according to claim 1 of the present invention is achieved. When the liquid refrigerant is sucked in at the minimum step, the amount of the liquid refrigerant to be sucked is small for a short time. Although no new liquid refrigerant is sucked in the next extremely low step, a small amount of liquid refrigerant that has already been sucked can be discharged from the compressor (3).

FIG. 4 shows another embodiment of the present invention.
The operation | movement which performs control which circulates a refrigerant | coolant and lubricating oil using the solenoid valve (20) for expansion valve opening / closing, and the solenoid valve (17) for capillaries is shown. The operation starts from step b1, and in step b2, the expansion valve opening / closing solenoid valve (20) is opened,
The solenoid valve (17) for the capillary is closed. Step b3
Then, the start of the compressor (3) as shown in FIGS. 2 and 3 is started. Since high pressure is applied to the pressure equalizing pipe (26) via the expansion valve opening / closing solenoid valve (20), the expansion valve is in a valve closed state, and the high pressure side and the low pressure side are separated. In step b4, the low pressure on the suction side of the compressor (3) is detected by the low pressure detector (2).
5), and determines whether the pressure is equal to or lower than a predetermined lower reference pressure. When the pressure becomes equal to or lower than the lower reference pressure, the expansion valve opening / closing solenoid valve (20) is closed and the capillary solenoid valve (17) is opened in step b5. Step b
When Step 5 is completed or when the condition is not satisfied in Step b4, it is determined in Step b6 whether the low pressure exceeds the upper reference. When the condition is satisfied, at step b7, the expansion valve opening / closing solenoid valve (20) is opened and the capillary solenoid valve (17) is closed. When step b7 is completed or when the condition is not satisfied in step b6, it is determined in step b8 whether or not the start-up operation shown in FIGS. 2 and 3 is completed. If not, the process returns to step b4. If it has been completed, the control also ends in step b9.

By controlling the opening and closing of the expansion valve (6) as described above, the compressor (3) operates so that the low pressure on the suction side falls between the lower reference and the upper reference. The refrigerant can be reliably sent to the air-side heat exchanger (5), which is a condenser, without excessively sucking the refrigerant and causing liquid compression or the like. In addition, the lubricating oil can be reliably circulated. The expansion valve (6) is an external pressure equalizing type temperature-sensitive type, and the pressure of the pressure equalizing pipe (26) is changed by the expansion valve opening / closing solenoid valve (20). Although opening and closing are performed, it is also possible to open and close at regular intervals by a timer using an electric expansion valve or the like that can be directly opened and closed. Further, instead of the method of detecting the suction pressure of the compressor (3) and opening and closing the external pressure equalizing type expansion valve (6) based on the pressure of the pressure equalizing pipe (26), an electric signal for pressure detection is used directly. The electric expansion valve can also be opened and closed. Also, the same effect can be obtained by indirectly controlling the opening and closing of the external pressure equalizing type expansion valve (6) based on the pressure of the pressure equalizing pipe at predetermined time intervals by a timer. However, detecting the suction pressure of the compressor (3) and keeping it within a predetermined range can more reliably avoid the possibility of extremely low pressure.

FIG. 5 shows a schematic refrigerant piping system of a refrigeration system (30) according to still another embodiment of the present invention. In this embodiment, portions corresponding to those in the embodiment of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, a refrigerant regulator (31) is provided between the air-side heat exchanger (5) and the expansion valve (6). A pipeline including the expansion valve opening / closing solenoid valve (20) and the capillary (21) is connected between the refrigerant regulator (31) and the suction side of the compressor (3). A temperature-sensitive cylinder (32) is attached to the suction side of the compressor (3), and controls the degree of superheat of the expansion valve (6). The capacity of the compressor (3) is controlled by switching the capacity switching valves (33a, 33b, 33c). The four-way switching valve (34) switches between a state in which the refrigeration apparatus (31) is operated in a refrigeration operation and a state in which the refrigeration apparatus is operated in a defrost operation. The control device (35) performs the same control as the control means (10) in FIG.

FIG. 6 shows a schematic refrigerant piping system according to still another embodiment of the present invention. In this embodiment, portions corresponding to the embodiment of FIGS. 1 and 5 are denoted by the same reference numerals, and description thereof will be omitted. In the refrigerating device (40) of the present embodiment, using the two compressors (3a) and (3b), the control device (45) controls the unloading device (7a) and the unloading device (7b). Are respectively controlled. In the control using two compressors (3a, 3b), 0% stops the operation of both compressors, and both operate at extremely low steps.
20% to operate at the minimum step of 40% for only one unit
Start-up operation is performed using the three stages. 2 of minimum steps
In the 0% operation, only the compressors (3a, 3b) that are different from the one that was operating immediately before are operated. When starting the operation from the stop state, it is determined that a specific compressor is operated. At the time of normal control, a step of 2
When shifting to the lowest step of 0%, the compressor that was started first is stopped. Further, when the operation is performed at the minimum step of 20% and the refrigerating capacity is to be increased, the other stopped compressor is started up by performing the above-described start control.

In the above description, although the refrigerating apparatus is started from a stopped state, the refrigerating apparatus is also started immediately after switching between refrigeration and heating or between refrigeration and defrost by a four-way switching valve or the like, or at the end thereof. If it is, smooth movement of the refrigerant can be performed.

[0028]

As described above, according to the present invention, the control means (10) controls the operation of the compressor (3) when the compressor (3) is started from an operation stop state, or when the defrost operation starts and ends. Operating at an extremely low step of the refrigerating capacity of
Since the operation in the minimum step is repeatedly performed, the liquid refrigerant accumulated in the evaporator can be quickly transferred to the condenser side while preventing liquid compression, so that the transition to the normal operation can be smoothly performed. . Since the operation is performed by repeating the extremely low step and the minimum step, even if the refrigeration capacity becomes excessive at the minimum step, it can be started with an appropriate refrigeration capacity, and the thermostat of the compressor due to excessive capacity may be removed. It is possible to reduce the repetition frequency of starting and stopping and to shorten the life of the compressor (3).

Further, according to the present invention, after the operation has been stopped for a long time, the number of repetitions of the extremely low step and the minimum step at startup is increased, so that a large amount of liquid refrigerant is stored in the evaporator. Even so, it is possible to reliably transfer to the condenser side.

Further, according to the present invention, when the number of start / stop of the compressor (3) stored in the storage means (23) is larger than a reference within a predetermined time, an extremely low step at the time of startup is set. Since the number of repetitions with the minimum step is increased, the refrigerating capacity becomes excessive, so that the frequency of stopping and restarting the compressor (3) due to thermo-off is reduced, and the life of the compressor (3) is shortened. Can be prevented.

Further, according to the present invention, by controlling the opening and closing of the expansion valve (6), the refrigerant is prevented from flowing into the evaporator at one time and the liquid refrigerant is prevented from flowing into the compressor (3). While the liquid compression is prevented, the lubricating oil can be appropriately returned to the compressor (3).

According to the present invention, when the compressor (3) is started, the pressure of the pressure equalizing pipe (26) of the external pressure equalizing type temperature-sensitive expansion valve (6) is controlled to open and close, and the refrigerant evaporates. It can be controlled to smoothly transfer from the condenser to the condenser while avoiding liquid compression. Further, it is possible to prevent the compressor (3) from being extremely low in pressure and running out of lubricating oil.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic refrigerant piping system and an electrical configuration for control according to an embodiment of the present invention.

FIG. 2 is a time chart showing an operation state of the refrigeration apparatus (1) of FIG.

FIG. 3 is a flowchart corresponding to the operation state of FIG. 2;

FIG. 4 is a flowchart showing the operation of another embodiment of the present invention.

FIG. 5 is a refrigerant piping system diagram showing a schematic configuration of still another embodiment of the present invention.

FIG. 6 is a refrigerant piping diagram showing a schematic configuration of still another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1,30,40 Refrigeration device 2 Water side heat exchanger 3,3a, 3b Compressor 5 Air side heat exchanger 6 Expansion valve 7,7a, 7b Unload device 10 Control means 11 Timer 12 Counter 13 Inlet side temperature detector 14 Outlet temperature detector 16, 21 Capillary 17 Solenoid valve 18 Fan 19 Chilled water tank 20 Expansion valve opening / closing solenoid valve 22 Long time detecting means 23 Storage means 35, 45 Controller

Continued on the front page (72) Inventor Takashi Kawagishi 1-1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd.Yodogawa Works (72) Inventor Katsuyoshi Matsuura 1304, Kanaokacho, Sakai-shi, Osaka Daikin Industries Sakai Works, Ltd. Kanaoka factory

Claims (5)

[Claims] 1. A refrigerating apparatus (1) including a compressor (3) capable of controlling the capacity in a plurality of stages including an extremely low step having almost no refrigerating capacity and a lowest step having the lowest refrigerating capacity in a normal operation range. A timer (11) for measuring the operating time of the compressor (3), a counter (12) for setting a predetermined number of times, and a timer when starting from a stopped state or when starting and ending defrost operation. A state in which the compressor (3) is operated in an extremely low step for a predetermined time measured by (11), and a state in which the compressor (3) is operated in the minimum step for a predetermined time measured by the timer (11). And control means (10) for controlling the compressor (3) to operate in the normal operation range after performing the start-up operation repeatedly until the number set in the counter (12) is reached. And a refrigeration apparatus characterized by the following. 2. A control device according to claim 1, further comprising a long-time detecting means for detecting whether or not a long time equal to or longer than a predetermined time has elapsed after the operation of the compressor is stopped. 2. The refrigeration system according to claim 1, wherein, when a long time elapses after the operation of the compressor (3) is stopped, the number of repetitions of the start-up operation is increased with reference to the long-time detection means (22). apparatus. 3. A storage unit (23) for storing a start / stop state of operation and stop of the compressor (3), wherein the control unit (10) determines in advance by referring to the storage unit (23). The refrigeration system according to claim 1 or 2, wherein when the number of start / stop operations of the compressor (3) within a time period is larger than a predetermined reference, the number of repetitions of the start-up operation is increased. 4. An expansion valve (6) that can be controlled to open and close, wherein the control means (10) repeatedly opens and closes the expansion valve (6) while repeating the extremely low step and the minimum step in the start-up operation. The refrigeration apparatus according to claim 1, wherein the refrigeration apparatus is controlled to perform the refrigeration. 5. The expansion valve (6) is an external pressure equalizing type temperature-sensitive expansion valve (6), and an electromagnetic valve provided between a high pressure side of the expansion valve (6) and a pressure equalizing pipe (26). A valve (20), a capillary (21) provided between the pressure equalizing pipe (26) and the suction side of the compressor (3), and the control means (10) includes: The solenoid valve (20) is opened, the expansion valve (6) is closed, and the solenoid valve (20) is closed so that the pressure on the suction side of the compressor (3) is within a predetermined range. The refrigeration apparatus according to claim 4, wherein control is performed to open the expansion valve (6).