JPH10288426A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a special operation possible wherein moisture included in a refrigerant circuit is allowed to reach a drier as liquid water by providing a temperature detecting device for effecting operation while refrigerant temperature range is being held in a refrigerator provided with a compressor, a condenser, a drier, an expansion mechanism and an evaporator. SOLUTION: A refrigerant circuit of a refrigerator is formed by connecting a compressor 1, a condenser 2, an expansion valve 3, an evaporator 4 and a drier 5 by use of pipes form a closed circuit. In this case a temperature detecting device 6 for detecting temperature of high pressure side refrigerant is installed and when temperature of the high pressure side refrigerant exceeds a specified temperature, the compressor 1 is stopped. And when the temperature becomes the specified temperature or lower, the compressor is started again to keep the temperature of the high pressure side refrigerant within a temperature range lower than an ordinary operation temperature at which moisture and oil react with each other to form sludge. By such operation the included moisture does not turn into another substance and can reach the drier as liquid water to be effectively removed by the drier 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to removal of water in a refrigerant circuit and prevention of sludge generation in a refrigeration system.

[0002]

2. Description of the Related Art FIG.
FIG. 10 is a refrigerant circuit diagram of the conventional refrigeration apparatus shown in No. 9; In the figure, 1 is a refrigerant compressor, 2 is a condenser, 3 is an expansion mechanism, 4 is an evaporator, and 5 is a dryer provided between the condenser 2 and the expansion mechanism 3.

In a conventional refrigeration system having a closed refrigerant circuit as described above, when the refrigeration system is installed, the inside of the refrigerant circuit is evacuated, and then the refrigerant is sealed, for example. Water is prevented from being mixed in, but still a small amount of water may remain in the refrigerant circuit, so the remaining water is in a liquid state that is most easily removed by the dryer during normal operation. It is removed by a dryer 5 between the condenser 2 and the expansion mechanism 3.

[0004] A dryer is a so-called drying agent.
There are many substances used, such as silica gel. It is installed for the purpose of removing the water in the refrigerant, and absorbs the water in the liquid state best. As a general example, in a refrigeration system such as that described above at a supermarket or the like, which uses R22 which is a hydrochlorofluorocarbon-based refrigerant (hereinafter, referred to as an HCFC-based refrigerant), in normal operation, the refrigerant gas is heated to a high temperature by a compressor.・ Compressed into high-pressure gas and discharged. Then, the liquid is converted into a high-temperature and high-pressure liquid by the condenser. After that, it becomes low temperature and low pressure liquid by the expansion mechanism,
The gas becomes low-temperature and low-pressure gas in the evaporator and is sucked into the compressor, and this process is repeated. Since the temperature between the compressor and the condenser is the highest, and if there is moisture in the refrigerant circuit, the moisture is often gas or water vapor, and it is difficult to remove it with a dryer. I can't. Although the temperature between the condenser 2 and the expansion mechanism 3 is high, the moisture is often liquid, so that a dryer is provided at this location in most cases. Since the temperature between the expansion mechanism 3 and the evaporator 4 and the compressor 1 is low, moisture tends to be ice. Therefore, it is rare to provide a dryer at this position.

[0005] The refrigeration system may be provided with an injection (hereinafter referred to as INJ) circuit (not shown). The INJ circuit is for returning the condensed liquid refrigerant to the compressor to prevent the temperature of the refrigerant compressed by the compressor from becoming high, and for evaporating the refrigerant to lower the refrigerant gas temperature. For example, in a refrigeration apparatus using R22, the flow rate of the INJ refrigerant is increased when the discharge gas temperature is 117 ° C. or more, and the INJ refrigerant flow rate is 105 ° C. or less.
An electromagnetic valve is provided in the INJ circuit in order to reduce the flow rate of the J refrigerant, and controls so that the high-pressure side refrigerant temperature is always within a predetermined temperature range.

[0006]

As long as a small amount of water is mixed in the refrigerant circuit, there is no problem in operation if a dryer is installed as usual, but as a practical problem, a refrigerator and a cooler are locally installed. In order to complete the refrigerant circuit by connecting pipes and the like, if vacuuming and charging of the refrigerant are also combined, it takes time and labor for construction work, and it is often impossible to remove moisture properly. For this reason, a large amount of water is mixed into the refrigerant circuit together with air and the like. In addition, moisture also adsorbs to the oil of the refrigerator, so that moisture enters the refrigerant circuit even when the refrigerator oil is sealed or added.

When the moisture remaining in the refrigerant circuit is removed by a dryer during normal operation, the moisture may become ice in a low-temperature portion between the expansion mechanism and the compressor before reaching the dryer, or the compressor and the condenser may be removed. In the meantime, sludge is generated by reacting with the oil in the high temperature part, and this becomes clogged in the thin tube, the heat exchanger, and the expansion mechanism. Therefore, the water cannot reach the dryer and cannot be completely removed, and there is a problem that the clogging of the equipment by the generated sludge or ice causes a reduction in the performance of the refrigeration system or a failure.

FIG. 11 shows the relationship between the discharge gas temperature and sludge generation. This shows the refrigerant temperature and the decomposition rate of the refrigerant when the metal catalyst is put into the refrigerant R22 and the naphthalene-based oil and 40 ppm of water is mixed. The decomposition of the refrigerant leads to the generation of sludge. From this figure, it can be seen that the higher the refrigerant temperature, the more easily the refrigerant is decomposed. In this case, the discharge gas temperature is about 127 ° C
As described above, the refrigerant starts to decompose. However, when a large amount of water enters the refrigeration system, sludge is generated even at a lower temperature. Attempting to operate at a low temperature at which sludge is not generated causes problems such as a lack of required refrigeration capacity.

In addition, HCFCs whose use will be regulated in the future
FIG. 12 shows that a hydrofluorocarbon-based refrigerant (hereinafter, referred to as an HFC-based refrigerant) or a mixed refrigerant containing an HFC-based refrigerant is used instead of the system-based refrigerant. This indicates the relationship between the refrigerant temperature and the hydrolysis rate of the refrigerant when moisture is mixed in the HCFC-based refrigerant and the HFC-based refrigerant. This figure shows that the HFC-based refrigerant is more easily hydrolyzed.

FIG. 13 shows a chemical formula of a hydrolysis reaction of an ester compound. As shown in this reaction formula, there is a problem that ester-based refrigerant oil and water, which are considered to be used as a new refrigerant, act to cause hydrolysis, so that water mixed in the refrigerant circuit is removed as soon as possible. Must be kept.

According to the present invention, a specific operation is performed such that the water mixed in the refrigerant circuit reaches the dryer as liquid water, and the water is accurately removed by the dryer.

[0012]

According to a first aspect of the present invention, there is provided a refrigeration apparatus having a refrigerant circuit including a compressor, a condenser, a dryer, an expansion mechanism, and an evaporator. It is provided with a temperature detecting device for performing the operation while maintaining the range.

In a refrigeration apparatus according to a second aspect of the present invention, in a refrigeration apparatus having a refrigerant circuit including a compressor, a condenser, a dryer, an expansion mechanism, and an evaporator, the refrigerant temperature on the high-pressure side is normally operated for a specific time. A temperature detecting device for operating in a temperature range restricted so as to be lower than the temperature is provided.

According to a third aspect of the present invention, there is provided a refrigeration apparatus having a refrigerant circuit including a compressor, a condenser, a dryer, an expansion mechanism, and an evaporator. A temperature detecting device is provided for performing operation in a temperature range restricted so as to be higher than the operating temperature.

According to a fourth aspect of the present invention, there is provided a refrigeration apparatus having a refrigerant circuit including a compressor, a condenser, a dryer, an expansion mechanism, and an evaporator. And a temperature detecting device for operating in a temperature range in which the refrigerant temperature on the low pressure side is lower than the normal operating temperature.

The refrigeration apparatus according to the fifth aspect of the present invention includes means for detecting the refrigerant temperature on the high pressure side of the refrigerant circuit, and starts and stops the compressor based on the detected temperature.

The refrigeration apparatus according to a sixth aspect of the present invention includes means for detecting the temperature of the refrigerant on the high pressure side of the refrigerant circuit, and controls the flow rate of the injection refrigerant flowing into the compressor based on the detected temperature.

In a refrigeration apparatus according to a seventh aspect of the present invention, the compressor is operated at a low speed by changing the input power supply of the compressor.

The refrigeration apparatus according to the eighth aspect of the present invention includes means for detecting the refrigerant pressure on the low pressure side of the refrigerant circuit, and starts and stops the compressor based on the detected pressure.

The refrigeration apparatus according to the ninth aspect is provided with means for operating the condenser fan at full speed, thereby reducing the pressure on the high pressure side.

[0021] In the refrigeration apparatus according to the tenth aspect,
Means are provided for flowing the high-pressure side refrigerant to the low-pressure side, whereby the amount of circulating refrigerant can be reduced.

In the refrigeration apparatus according to the eleventh aspect,
In a refrigerating apparatus equipped with two or more compressors, the refrigerating machine includes means capable of operating at least one or more compressors less than the number of mounted compressors.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 shows a first embodiment of the present invention and shows a refrigerant circuit of a refrigeration apparatus. In the figure, 1 is a compressor, 2 is a condenser, 3 is an expansion valve, 4 is an evaporator, 5 is a dryer, 6 is a temperature detecting device for measuring the refrigerant temperature on the high pressure side. FIG. 2 shows a flowchart of the control.

When the refrigerant temperature on the high pressure side detected by the temperature detecting device 6 exceeds a predetermined temperature T1, for example, 100 ° C., the compressor 1 is stopped. Further, a predetermined temperature T
2. When the temperature becomes 70 ° C. or lower, for example, the compressor 1 is started again, so that the temperature of the refrigerant on the high pressure side is constantly changed to a normal operating temperature T3 at which moisture and oil react to generate sludge, and a temperature lower than 127 ° C. The operation can be maintained between T1 and T2, which is the range. It is necessary to set T1 to T3 to temperatures corresponding to the respective types of the refrigerant.

Accordingly, the mixed water does not change into another substance and can reach the dryer 5 as liquid water, so that the mixed water can be removed by the dryer 5. The operation state is changed for a predetermined time, for example, a refrigerant circulation amount Gr (kg / h) of the refrigerant circuit and a refrigerant charging amount Ga (k).
If g) is known, the time Tr = Ga / Gr in which all the refrigerant makes one round of the refrigerant circuit is known, so at least:
The time Tr during which all the refrigerant makes one round of the refrigerant circuit,
When the high-pressure side refrigerant temperature is operated in the predetermined temperature range T1 to T2, the compressor 1 is stopped after the normal operation, for example, when the high-pressure side refrigerant temperature is 135 ° C. Is a stable and reliable refrigeration apparatus with less failure due to no generation of sludge in the high temperature part and no generation of ice in the low temperature part because there is no moisture in the refrigerant circuit.

Here, the description has been given of the case where the water removal operation is performed in a temperature range in which the refrigerant temperature on the high pressure side is limited to be lower than the normal operation for a specific time. In the meantime, the same operation and effect can be obtained by performing the moisture removal operation in a temperature range in which the low-pressure side refrigerant temperature is limited to be higher than the normal operation temperature. Further, during the specific time, the refrigerant temperature on the high pressure side is lower than the normal operation, and, to perform the water removal operation in a temperature range that is limited so that the refrigerant temperature on the low pressure side is higher than the normal operation temperature. Is also good. The control of the water removal operation is performed by a temperature detecting device having a configuration similar to that of the temperature detecting device 6 shown in FIG. 1 and capable of controlling the refrigerant temperature within an appropriate temperature range.

By performing such a water removal operation after the installation of the refrigeration system or after the repair service, etc., a highly reliable refrigeration system capable of performing a stable operation after the installation of the refrigeration system or after the repair service, etc. Driving method can be provided.

Embodiment 2 FIG. 3 is a view showing a second embodiment of the present invention, and shows a refrigerant circuit of a refrigeration apparatus. The same parts as those in FIG. 7
Is a temperature detecting device for measuring the refrigerant temperature on the high pressure side. 8 is an INJ circuit; 9 is a solenoid valve;
Adjust refrigerant flow. FIG. 4 shows a flowchart of the control.

The INJ refrigerant flow rate is controlled by the solenoid valve 9 so that the discharge gas temperature detected by the temperature detecting device 7 becomes lower than the normal operating temperature T4 at which water and oil react to generate sludge, for example, 127 ° C. To adjust the refrigerant temperature on the high pressure side to a predetermined range T5 to T6, e.g.
Operate at 70 ° C. It is necessary to set T4 to T6 to a temperature corresponding to each type of refrigerant.

Accordingly, the mixed water does not change into another substance and can reach the dryer 5 as liquid water, so that the mixed water can be removed by the dryer 5. If this operation is performed for at least the time Tr during which all the refrigerant makes one round of the refrigerant circuit, the subsequent normal operation does not generate moisture in the refrigerant circuit, so that no sludge is generated in the high-temperature part and ice is generated in the low-temperature part. A stable and reliable refrigeration system with less failure due to no generation.

Embodiment 3 FIG. 5 shows a third embodiment of the present invention. The same parts as those in FIG. In FIG. 5, reference numeral 10 denotes an inverter.

An input power supply frequency of the compressor 1 is made lower than a normal operation frequency H1, for example, 50 Hz by an inverter 10 capable of changing a power supply frequency of the compressor,
When the compressor 1 is operated at a low speed, the refrigerant temperature on the high pressure side is changed to a normal operating temperature T7 at which moisture and oil react to generate sludge, for example, a temperature range T8 to T lower than 127 ° C.
9, operate at 100 ° C to 70 ° C, for example. It is necessary to set T7 to T9 to a temperature corresponding to each type of refrigerant.

Further, the compressor 1 may be operated at a low speed by setting the voltage value or the current source to a value lower than that in the normal operation by using a transformer or the like.

By doing so, the temperature of the refrigerant on the high pressure side can be lowered, and the mixed water can reach the dryer 5 as liquid water without changing to other substances, so that the mixed water is removed by the dryer 5. can do.
If this operation is performed for at least the time Tr during which all the refrigerant makes one round of the refrigerant circuit, the subsequent normal operation has no moisture in the refrigerant circuit, so that no sludge is generated in the high-temperature portion,
A stable and highly reliable refrigeration system with few failures due to no formation of ice in the low temperature part.

Embodiment 4 FIG. FIG. 6 shows a fourth embodiment of the present invention, and shows a refrigerant circuit of a refrigeration apparatus. The same parts as those in FIG. In FIG. 6, reference numeral 11 denotes a pressure detecting device for measuring the refrigerant pressure on the low pressure side. FIG. 7 is a flowchart of the control.

When the low pressure side refrigerant pressure detected by the pressure detecting device 11 is lower than the predetermined pressure P1, the compressor 1 is stopped. Also, a predetermined pressure P2 (P2> P1)
When the temperature becomes higher, the compressor 1 is started again, so that the refrigerant evaporation temperature in the evaporator 4 is always kept higher than a normal operating temperature range T10 to T11, for example, -40 ° C to -5 ° C. The operation is performed in a temperature range T12 to T13, for example, 0 ° C to 15 ° C so as not to change into ice. P1
P2 needs to be set to a pressure corresponding to each type of refrigerant.

Therefore, the mixed water does not change into another substance and can reach the dryer 5 as liquid water, so that the mixed water can be removed by the dryer 5. If this operation is performed for at least the time Tr during which all the refrigerant makes one round of the refrigerant circuit, the subsequent normal operation does not generate moisture in the refrigerant circuit, so that no sludge is generated in the high-temperature part and ice is generated in the low-temperature part. A stable and reliable refrigeration system with less failure due to no generation.

Embodiment 5 FIG. 8 shows a fifth embodiment of the present invention. The same parts as those in FIG. In FIG. 8, reference numeral 12 denotes a condenser cooling fan.

The capacity of the condenser is expressed by equation (1). Qc = Rc · ΔT = Rc (Tc−Tair) (1) Rc: a constant obtained from the air volume of the heat exchanger, the specific heat of air, the heat transfer rate of the condenser, and the heat transfer area of the condenser Tc: the condensation temperature Tair: According to the outside air temperature, the cooling fan 12 of the condenser 2 is operated at full speed,
When the air flow rate is larger than in the normal operation, the value of Rc in Expression (1) increases. Assuming that the condensing capacity Qc and the outside air temperature Tair do not change at that time, the condensing temperature Tc decreases, so that the refrigerant temperature on the high pressure side can be lowered.

As a result, the refrigerant temperature on the high pressure side is changed to the normal operating temperature T at which sludge is formed by the reaction of moisture and oil.
14. For example, a temperature range T15 to T1 lower than 127 ° C.
6, It can be operated at, for example, 100 ° C to 70 ° C.
It is necessary to set T14 to T16 to a temperature corresponding to each type of refrigerant.

Therefore, the mixed water does not change into another substance and can reach the dryer 5 as liquid water, so that the mixed water can be removed by the dryer 5. If this operation is performed for at least the time Tr during which all the refrigerant makes one round of the refrigerant circuit, the subsequent normal operation does not generate moisture in the refrigerant circuit, so that no sludge is generated in the high-temperature part and ice is generated in the low-temperature part. A stable and reliable refrigeration system with less failure due to no generation.

Embodiment 6 FIG. FIG. 9 shows a sixth embodiment of the present invention. The same parts as those in FIG. In FIG. 9, 13 is a bypass circuit for flowing the high-pressure side refrigerant to the low-pressure side, and 14 is an electromagnetic valve.

Equation (1) can be rewritten as follows. Qc = Rc (Tc−Tair) = Gc (Id−Isc) (2) Gc: Refrigerant circulation amount Id: Compressor discharge gas enthalpy Ise: Refrigerant gas enthalpy at the outlet of the condenser Open solenoid valve 14 and bypass When a predetermined amount Gb of the high-pressure side refrigerant is caused to flow to the low-pressure side by the circuit 13, the refrigerant circulation amount Gc is reduced by Gb in the equation (2). Assuming that the time constant Rc, the outside air temperature Tair, the compressor discharge gas enthalpy Id, and the refrigerant gas enthalpy Is at the outlet of the condenser do not change, the refrigerant condensation temperature Tc decreases, so that the refrigerant gas temperature on the high pressure side can be lowered. The same can be said for the evaporator 4 side. When the refrigerant circulation amount decreases, the refrigerant evaporation temperature increases, so that the refrigerant temperature on the high pressure side can be lowered.

As a result, the temperature of the refrigerant on the high pressure side is changed to the normal operating temperature T at which sludge is formed by the reaction of moisture and oil.
17, for example, a temperature range T18 to T1 lower than 127 ° C.
9. A temperature range T which can be operated at, for example, 100 ° C. to 70 ° C., and is maintained at a temperature higher than a normal operating temperature range T20 to T21, for example, −40 ° C. to −5 ° C., so that mixed water does not change into ice
It can be operated at 22-T23, e.g. It is necessary to set T17 to T23 to a temperature corresponding to each type of the refrigerant.

Therefore, the mixed water does not change into another substance and can reach the dryer 5 as liquid water, so that the mixed water can be removed by the dryer 5. If this operation is performed for at least the time Tr during which all the refrigerant makes one round of the refrigerant circuit, the subsequent normal operation does not generate moisture in the refrigerant circuit, so that no sludge is generated in the high-temperature part and ice is generated in the low-temperature part. A stable and reliable refrigeration system with less failure due to no generation.

Embodiment 7 FIG. FIG. 10 shows a seventh embodiment of the present invention. The same parts as those in FIG. In FIG.
Reference numeral 16 denotes a compressor which is similar to the compressor 1 or has a different capacity.

As shown in FIG. 10, in a refrigeration system having two or more compressors, by operating either the compressor 1 or the compressor 16, the amount of refrigerant circulation Gc in the equation (2) is usually reduced. Make less than driving. The time constant R
c, outside air temperature Tair, compressor discharge gas enthalpy Id,
Assuming that the refrigerant gas enthalpy Is at the outlet of the condenser does not change, the refrigerant condensation temperature Tc decreases, so that the refrigerant gas temperature on the high pressure side can be reduced. The same can be said for the evaporator side. When the refrigerant circulation amount is small, the refrigerant evaporation temperature increases, so that the refrigerant temperature on the low pressure side can be increased.

As a result, the temperature of the refrigerant on the high pressure side is changed to a normal operating temperature range T24 in which moisture and oil react to generate sludge, for example, a temperature range T25 to T lower than 127 ° C.
26, for example, it can be operated at 100 ° C. to 70 ° C. and keeps the refrigerant temperature on the low pressure side higher than the normal operating temperature range T27 to T28, for example, −40 ° C. to −5 ° C., so that the mixed water does not change into ice. Temperature range T29 to T30, for example, 0 ° C.
Can operate at ~ 15 ° C. It is necessary to set T24 to T30 to a temperature corresponding to each type of refrigerant.

Accordingly, the mixed water does not change into another substance and can reach the dryer 5 as liquid water, so that the mixed water can be removed by the dryer 5. If this operation is performed for at least the time Tr during which all the refrigerant makes one round of the refrigerant circuit, the subsequent normal operation does not generate moisture in the refrigerant circuit, so that no sludge is generated in the high-temperature part and ice is generated in the low-temperature part. A stable and reliable refrigeration system with less failure due to no generation.

Embodiment 8 FIG. By combining two or more of the first to seventh embodiments, the temperature of the refrigerant on the high pressure side is changed to a normal operating temperature T31 at which sludge is generated by the reaction of moisture and oil, for example, 12
Temperature range T32 to T33 lower than 7 ° C, for example, 100 ° C
-30 ° C., and a temperature range T36-T37 where the refrigerant temperature on the low pressure side is kept higher than the normal operating temperature range T34-T35, for example, -40 ° C .-- 5 ° C., and the mixed water does not change into ice. , For example, at 0 ° C. to 15 ° C. It is necessary to set T31 to T37 to a temperature corresponding to each type of the refrigerant.

Accordingly, the mixed water does not change into another substance and can reach the dryer 5 as liquid water, so that the mixed water can be removed by the dryer 5. If this operation is performed for at least the time Tr during which all the refrigerant makes one round of the refrigerant circuit, the subsequent normal operation does not generate moisture in the refrigerant circuit, so that no sludge is generated in the high-temperature part and ice is generated in the low-temperature part. A stable and reliable refrigeration system with less failure due to no generation.

Embodiment 9 FIG. In performing one of the above-described first to eighth embodiments, in each operation, an operation such as a timer is performed in order to perform an operation for a time Tr during which at least all the refrigerant makes one round of the refrigerant circuit. By providing the controller, a test operation aimed at removing water from the refrigerant circuit can be performed reliably and by anyone, and a stable and reliable refrigeration apparatus with few failures can be provided.

[0053]

According to the refrigerating apparatus of the first invention,
Since the water removal operation is performed while maintaining the refrigerant temperature range for allowing the water mixed in the refrigerant circuit to reach the dryer as liquid water, a highly reliable refrigeration apparatus that can perform stable operation can be provided.

According to the refrigeration apparatus of the second aspect, the water removal operation is performed in a temperature range in which the refrigerant temperature on the high pressure side is limited so as to be lower than the normal operation, so that stable operation can be performed. A highly reliable refrigeration system can be provided.

According to the refrigeration apparatus of the third aspect, the water removal operation is performed within a temperature range in which the low-pressure side refrigerant temperature is restricted to be higher than the normal operation temperature. And a highly reliable refrigeration system that can be provided.

According to the refrigeration system of the fourth aspect, the refrigerant temperature on the high pressure side is lower than that in the normal operation, and the refrigerant temperature on the low pressure side is restricted to be higher than the normal operation temperature. Since the water removal operation is performed, it is possible to provide a highly reliable refrigeration apparatus capable of performing stable operation.

According to the refrigeration apparatus of the fifth aspect, the means for detecting the refrigerant temperature on the high pressure side of the refrigerant circuit is provided, and the compressor is started / stopped based on the detected temperature. The temperature of the refrigerant in the refrigerant circuit can be set within a predetermined temperature range, and the water mixed in the refrigerant circuit does not change into another substance. Therefore, the water in the refrigerant circuit can be reliably removed by the dryer.

According to the refrigeration apparatus of the sixth aspect, the means for detecting the refrigerant temperature on the high pressure side of the refrigerant circuit is provided, and the flow rate of the injection refrigerant flowing into the compressor is controlled based on the detected temperature. In addition, the refrigerant temperature on the high pressure side can be set within a predetermined temperature range, and the water mixed in the refrigerant circuit does not change into another substance, so that the water can be reliably removed by the dryer. In addition, the number of times the compressor is started and stopped during the test operation can be reduced.

According to the refrigeration apparatus of the seventh aspect, the compressor is operated at low speed by changing the input power supply of the compressor, so that the high-pressure side refrigerant temperature is set within a predetermined temperature range. Since the water mixed in the refrigerant circuit does not change into another substance, the water in the refrigerant circuit can be reliably removed by the dryer. In addition, power consumption during test operation can be reduced.

According to the refrigeration apparatus of the eighth aspect, the means for detecting the refrigerant pressure on the low pressure side of the refrigerant circuit is provided, and the compressor is started / stopped by the detected pressure. The temperature can be set within a predetermined temperature range, the water mixed in the refrigerant circuit does not change into another substance, and the water can be reliably removed by the dryer.

According to the refrigeration apparatus of the ninth aspect, the means for operating the fan of the condenser at full speed is provided so as to reduce the pressure on the high pressure side. Since the water mixed in the refrigerant circuit does not change into another substance, the water can be reliably removed by the dryer. Further, the test operation time can be reduced.

According to the refrigeration apparatus of the tenth aspect,
A means for flowing the high-pressure side refrigerant to a low pressure is provided so that the refrigerant circulation amount can be reduced, so that the high-pressure side refrigerant temperature and the low-pressure side refrigerant temperature can be within a predetermined temperature range, and the refrigerant circuit Since the water mixed into the inside does not change into another substance, the water can be surely removed by the dryer.

According to the refrigeration apparatus of the eleventh aspect,
In a refrigeration system having two or more compressors, at least one or more compressors can be operated in a smaller number than the number of compressors. Therefore, the refrigerant temperature on the high pressure side and the refrigerant temperature on the low pressure side are set to a predetermined value. Since the temperature can be set within the temperature range and the water mixed in the refrigerant circuit does not change into another substance, the water can be reliably removed by the dryer.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart of the refrigeration apparatus showing the first embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 2 of the present invention.

FIG. 4 is a flowchart of a refrigeration apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 3 of the present invention.

FIG. 6 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 4 of the present invention.

FIG. 7 is a flowchart of a refrigerating apparatus according to Embodiment 4 of the present invention.

FIG. 8 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 5 of the present invention.

FIG. 9 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 6 of the present invention.

FIG. 10 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 7 of the present invention.

FIG. 11 is a diagram illustrating a relationship between a refrigerant temperature and a refrigerant decomposition rate.

FIG. 12 is a diagram showing a relationship between a refrigerant temperature and a hydrolysis rate of the refrigerant.

FIG. 13 is a view showing a chemical formula of a hydrolysis reaction of an ester compound.

FIG. 14 is a refrigerant circuit diagram of a conventional device disclosed in JP-A-6-235569.

[Explanation of symbols]

1 compressor, 2 condenser, 3 expansion mechanism, 4 evaporator,
Reference Signs List 5 dryer, 6 temperature detecting device, 7 INJ temperature detecting device, 8 INJ refrigerant circuit, 9 INJ solenoid valve, 10 inverter, 11 pressure measuring device, 12
Fan, 13 bypass circuit, 14 solenoid valve for bypass circuit, 15 compressor, 16 compressor.

Claims (11)

[Claims] 1. A compressor, a condenser, a dryer, an expansion mechanism,
A refrigeration apparatus having a refrigerant circuit including an evaporator, wherein a refrigeration apparatus is provided with a temperature detecting device for operating while maintaining a refrigerant temperature range for a specific time. 2. A compressor, a condenser, a dryer, an expansion mechanism,
In a refrigerating apparatus having a refrigerant circuit including an evaporator, a device for temperature detection is provided for performing operation in a temperature range in which a high-pressure side refrigerant temperature is limited to be lower than normal operation for a specific time. A refrigeration apparatus characterized by the above-mentioned. 3. A compressor, a condenser, a dryer, an expansion mechanism,
In a refrigerating apparatus having a refrigerant circuit composed of an evaporator, for a specific time, a temperature detecting device for performing operation in a temperature range in which the low-pressure side refrigerant temperature is restricted to be higher than a normal operating temperature is provided. A refrigeration device characterized by the following. 4. A compressor, a condenser, a dryer, an expansion mechanism,
In a refrigeration system having a refrigerant circuit composed of an evaporator, during a specific time, the refrigerant temperature on the high pressure side is lower than in normal operation,
And a refrigeration apparatus provided with a temperature detecting device for performing operation in a temperature range in which the low-pressure side refrigerant temperature is restricted to be higher than a normal operation temperature. 5. Means for detecting a refrigerant temperature on the high pressure side of the refrigerant circuit, and starting and activating the compressor based on the detected temperature.
The refrigeration apparatus according to claim 1, 2 or 4, wherein the refrigeration is stopped. 6. The refrigerant circuit according to claim 1, further comprising means for detecting a refrigerant temperature on a high pressure side of the refrigerant circuit, wherein a flow rate of the injection refrigerant flowing into the compressor is controlled by the detected temperature. The refrigeration apparatus according to claim 4. 7. The refrigeration apparatus according to claim 1, wherein the compressor is operated at a low speed by changing an input power supply of the compressor. 8. A means for detecting a refrigerant pressure on the low pressure side of the refrigerant circuit, wherein the detected pressure is used to start / start the compressor.
The refrigeration apparatus according to claim 1, 3 or 4, wherein the refrigeration is performed. 9. The refrigerating apparatus according to claim 1, further comprising means for operating the fan of the condenser at full speed, whereby the pressure on the high pressure side is reduced. 10. The refrigeration system according to claim 1, further comprising means for flowing the high-pressure refrigerant to the low-pressure side, whereby the amount of circulating refrigerant can be reduced. 11. A refrigerating apparatus having two or more compressors, wherein at least one of the compressors has means for operating less than the number of mounted compressors. Item 5. A refrigeration apparatus according to any one of Items 4.