JPH0791749A - Refrigerator - Google Patents

Abstract

PURPOSE:To provide a reliable refrigerator in which freezer oil is smoothly returned to a compressor without stagnating at low ambient temperature even if the mutual solubility of the freezer oil and refrigerant is low. CONSTITUTION:A flow speed of refrigerant within an inlet pipe 6a of a condenser 2 is detected by a flow speed meter 11. When this detected flow speed of refrigerant is less than a predetermined zero-penetration in an inlet pipe 6a of the condenser, a compressor cooling fan 9 is stopped. With such an arrangement as above, over-cooling of the compressor is prevented and the stagnation of the freezer oil in the pipe is restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator provided with a refrigeration cycle using a refrigerant having a poor mutual solubility and refrigerating machine oil.

[0002]

2. Description of the Related Art Conventionally, in a large domestic refrigerator, a compressor cooling fan is provided in a machine room for storing the compressor in order to prevent the compressor from overheating, and is synchronized with the operation of the compressor. The compressor cooling fan was driven to suppress the temperature rise of the compressor, ensuring stable operation of the refrigerator.

FIG. 13 is a refrigerating circuit diagram showing an example of a refrigerating cycle of a conventional refrigerator. In the figure, (1) is a compressor for compressing a refrigerant gas, and (2) is a high pressure discharged from the compressor (1). A condenser for condensing the refrigerant gas, (3) a capillary tube which is a decompression device, (4) an evaporator, (5) a header having a refrigerant amount adjusting function, and (6) connecting them to circulate the refrigerant. Piping, (7) is a refrigerating machine oil that has mutual solubility with the refrigerant, and serves to lubricate and seal the sliding part of the compressor (1), and stays at the bottom of the closed container of the compressor (1). There is. (8)
Are these compressors (1), condensers (2), capillary tubes
A refrigeration cycle comprising (3), an evaporator (4), a header (5) and a pipe (6).

Next, the operation of the refrigerating machine oil (7) will be described. The refrigerant compressed by the compressor (1) is discharged to the condenser (2). At this time, a part of the refrigerating machine oil (7) is discharged from the compressor (1) together with the refrigerant. Refrigerating machine oil (7) discharged from the compressor (1) has good fluidity because it has mutual solubility with the refrigerant,
It returns to the compressor (1) through the condenser (2), the capillary tube (3), the evaporator (4), and the header (5). Therefore refrigerator oil
(7) does not disappear from the compressor (1), and normal lubrication is possible.

[0005]

Recently, the use of various types of refrigerants in refrigerators has been studied as a countermeasure against CFC substitutes. However, when a refrigerating machine oil (7) and a refrigerant having poor mutual solubility are used, the pipe ( In 6), the refrigerant and the refrigerating machine oil (7) are separated to form a two-phase flow, and the refrigerant has a flow mode that pushes the refrigerating machine oil. Therefore, the circulating flow rate of the refrigerating machine oil (7) discharged from the compressor (1) together with the refrigerant to the compressor (1) is the circulating refrigerant flow velocity (=
Flow rate). That is, if the circulating refrigerant flow velocity is not higher than a certain level, the refrigerating machine oil taken out from the compressor (1) into the refrigeration cycle (8) stays in the pipe (6) and becomes difficult to return to the compressor (1).

Especially in a large refrigerator, since the pipe diameter is large,
Refrigerant flow velocity decreases, and refrigerating machine oil (7) easily accumulates. Further, when a compressor (1) having a small stroke volume is used as in a small refrigerator, the amount of circulating refrigerant becomes small and the refrigerating machine oil (7) may accumulate. Furthermore, when the temperature of the compressor (1) is lowered by driving the compressor cooling fan, or when the evaporation temperature is low at low outside air temperature, the compressor (1)
Since the amount of condensed refrigerant staying inside increases and the circulating refrigerant flow velocity decreases, the refrigerating machine oil (7) taken out from the compressor (1) stays inside the piping (6) of the refrigeration cycle (8), and the compressor ( It became more difficult to return to 1), and there were problems such as causing compressor trouble due to lubrication oil breakage. Further, when the refrigerating machine oil (7) taken out from the compressor (1) stagnates in the heat exchanger, the heat transfer efficiency of the heat exchanger may decrease, and the cooling performance of the refrigerator may deteriorate.

In a conventional refrigerator having a compressor cooling fan, the cooling fan is driven only in synchronization with the operation of the compressor. Therefore, when a refrigerant and refrigerating machine oil having poor mutual solubility are used, the compressor is compressed. The temperature of the machine was too low, and there was the above-mentioned problem.

FIG. 14 is a diagram for explaining the states of the refrigerant gas rising in the pipe (6) and the refrigerating machine oil (7) pushed by the refrigerant gas when the refrigerant and refrigerating machine oil having poor mutual solubility are used. From the lower end of the pipe (6), raise the refrigerant gas at a flow rate U _g ,
The vertical pipe annular counter-flow flow pattern formed by injecting the refrigerating machine oil (7) from the porous wall of the pipe (6) is shown. Plumbing (6)
When the velocity U _{g of the} refrigerant gas flowing upwardly in the chamber increases above a certain flow velocity, the refrigerating machine oil forms an oil film along the pipe wall and goes up against the pipe wall against its own weight. The refrigerant gas flow rate U _g 'at this time is referred to as a zero penetration flow rate. However, when the refrigerant gas flow rate U _g is small and falls below the zero penetration flow rate U _g ′, the oil film of the refrigerating machine oil (7) smoothly descends along the pipe wall.

In the refrigerator, the vertical tubular annular counterflow corresponds to the pipe (6) from the compressor (1) to the condenser (2). Especially in the condenser inlet, the gas density increases along with the radiator, for reducing the refrigerant gas flow rate, the circulation flow rate of refrigerant reduced low ambient temperature operation when the refrigerant flow rate U _g is zero penetration velocity U _g '
There is a high possibility that stagnation of the refrigerating machine oil (7) will occur.

The present invention has been made in order to solve the above-mentioned problems, and even if a refrigerant and refrigerating machine oil having poor mutual solubility are used, the refrigerating machine oil does not stay at a low outside air temperature, and the refrigerating machine oil is reliably retained. Return to the compressor aims to get a reliable refrigerator.

[0011]

According to a first aspect of the present invention, there is provided a refrigerator in which the refrigerant flow velocity detecting means for detecting the refrigerant flow velocity in the inlet pipe of the condenser and the detected value of the refrigerant flow velocity detecting means are A compressor cooling fan control means for stopping the driving of the compressor cooling fan when the value is equal to or less than a predetermined value is provided.

In the refrigerator according to the second aspect of the present invention, the refrigerant flow velocity detecting means for detecting the refrigerant flow velocity in the inlet pipe of the condenser and the detection value of the refrigerant flow velocity detecting means are set in advance. Compressor cooling fan control means for stopping the drive of the compressor cooling fan when the flow velocity value is below the zero penetration flow rate value of the inlet pipe of the condenser is provided.

According to a third aspect of the present invention, a refrigerator has a suction refrigerant temperature detecting means for detecting a refrigerant temperature in a suction pipe of a compressor, and a condenser refrigerant temperature detecting means for detecting a refrigerant temperature in a condenser. Means, an evaporator refrigerant temperature means for detecting the refrigerant temperature in the evaporator, and the values detected by these temperature detecting means, the refrigerant flow velocity in the inlet pipe of the condenser satisfies the zero penetration flow velocity of the inlet pipe or more. A compressor cooling fan control means for stopping the driving of the compressor cooling fan when the temperature is outside the preset temperature range is provided.

In the refrigerator according to the fourth aspect of the present invention, the outside air temperature detecting means for detecting the outside air temperature and the value detected by the outside air temperature detecting means are the refrigerant flow velocity in the inlet pipe of the condenser. When the temperature exceeds the zero penetration flow velocity of the inlet pipe and is outside the preset temperature range,
A compressor cooling fan control means for stopping the driving of the compressor cooling fan is provided.

[0015]

According to the first aspect of the present invention, when the refrigerant flow velocity in the inlet pipe of the condenser becomes equal to or lower than a predetermined value, the driving of the compressor cooling fan is stopped to prevent the compressor from being overcooled. The retention of refrigerating machine oil in the pipe is suppressed.

According to the second aspect of the present invention, when the refrigerant flow velocity in the inlet pipe of the condenser becomes equal to or lower than the preset zero penetration flow velocity value of the inlet pipe of the condenser, the cooling fan of the compressor is cooled. The drive is stopped, overcooling of the compressor is prevented, and refrigerating machine oil is prevented from staying in the pipe.

In the invention according to claim 3 of the present invention, when the refrigerant temperature in the suction pipe of the compressor, the refrigerant temperature in the condenser, and the refrigerant temperature in the evaporator are out of preset temperature ranges, The drive of the compressor cooling fan is stopped, overcooling of the compressor is prevented, and refrigerating machine oil is prevented from staying in the piping.

According to a fourth aspect of the present invention, when the outside air temperature is out of a preset temperature range, the driving of the compressor cooling fan is stopped, the compressor is prevented from being overcooled, and the inside of the pipe is prevented. Of refrigerating machine oil is suppressed.

[0019]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show the first embodiment, FIG. 1 is a configuration diagram, FIG. 2 is a block diagram of a control unit, and FIG. 3 is a flowchart for explaining a compressor cooling fan control operation. In the figure, (1) is a compressor, (2) is a condenser, (3) is a capillary tube which is a decompression device, (4) is an evaporator, (5) is a header,
(6) is piping, (7) is refrigerating machine oil, and (8) is refrigeration cycle. The above is the same as the conventional example shown in FIG.

(6a) is a condenser inlet pipe, (9) is a compressor cooling fan for forcibly cooling the compressor (1), (10) is a fan motor, and (11) is inside the condenser inlet pipe (6a). Of the refrigerant flow velocity detecting means for detecting the refrigerant flow velocity, (12) the refrigerator control unit, (13) in the control unit (12), when the detection value of the flow velocity meter (11) is less than or equal to a predetermined value, A compressor cooling fan control means for stopping the drive of the fan motor (10), (14) an internal temperature sensor for detecting the temperature in the refrigerator, and (15) a microcomputer (hereinafter referred to as a microcomputer constituting the control unit (12). It is called a microcomputer).
Further, in this embodiment, HFC-134a,
Hard alkylbenzene oil is used as the refrigerating machine oil (7).

Next, the control operation of the compressor cooling fan will be described with reference to the flowchart of FIG. First, step (2
The temperature detected by the inside temperature sensor (14) is taken in in 1), and this detected temperature is compared with a predetermined set value for the inside temperature set in advance in step (22), and if the detected value is lower than the set value. While proceeding to step (23) to stop the compressor (1),
The fan motor (10) is also stopped in step (24), and if the detected value is higher than the set value in step (22), the process proceeds to step (25) to operate the compressor (1).

During operation of the compressor (1), the detection value of the anemometer (11) is taken in in step (26), and in step (27) this detection value and a preset setting for the condenser inlet refrigerant flow velocity are set. If the detected value is equal to or exceeds the set value, proceed to step (28) to continue the fan motor (10) operation, and if the detected value is below the set value, ,
Proceed to step (29) to stop the fan motor (10).

As described above, in this embodiment, the compressor (1)
Drive the compressor cooling fan (9) in synchronization with the operation of
When the operating conditions are such that the compressor (1) is prevented from overheating and the refrigerant flow velocity decreases due to continuous operation at low ambient temperature, etc., and refrigerating machine oil (7) tends to stay, it is detected and a compressor cooling fan is detected. (9)
The drive is stopped.

The zero penetration flow rate value of the condenser inlet pipe (6a) is used as a predetermined set value for the preset condenser inlet refrigerant flow rate to be compared with the detected value of the flow velocity meter (11). . This zero penetration flow velocity value is obtained as follows. The semi-empirical formula for zero penetration flow velocity in gas-liquid two-phase flow is

[0025]

[Equation 1]

[0026] Where U _g ': Zero penetration flow velocity [m / s] U _g ": Dimensionless velocity g: Gravity acceleration = 9.80665 [m / s ² ] D: Pipe inner diameter [m] ρ _l : Refrigerator oil density = 867 [kg / m ³ ] ρ _g : Refrigerant gas density [kg / m ³ ]. There are the following four methods for obtaining U _g ".

Walls' method for small tube diameter direction 0.56 ≦ U _g “= C ≦ 1.00 (2) where C: constant

Modifie considering the surface tension of refrigerating machine oil
d-Walls method

[0029]

[Equation 2] Where σ: Refrigerator oil surface tension

Puchkina's method for large tube orientation

[0031]

[Equation 3] Here K _g : kutateladze number = 3.2 Nb = bond number

Richer's method for all tube diameters

[0033]

[Equation 4] Where Cw: wall friction constant = 0.008

U _g "determined by any of the above equations (2) to (8)
Substituting into equation (1), the zero penetration flow velocity U _g 'is obtained.

The refrigerant pressure on the condenser side of a general refrigerator is 1
About 0.3 [ata], the refrigerant HFC-134a at this time
Saturated vapor density of 49.9 [kg / m ³ ], the density ρ _l of refrigerating machine oil and hard alkylbenzene oil is 867 [kg /
m ³ ], and the inner diameter D of the condenser inlet pipe (6a) is 4 × 10 to ³
If [m], the zero penetration flow rate U _g 'is 0.1.
It becomes 8 [m / s]. Therefore, the setting value for the refrigerant flow velocity is 1.2 U _g '= 1.0 [m / s] in consideration of safety.

If the compressor cooling fan (9) is controlled as described above, the compressor (1) will not be overcooled even at low ambient temperature, so that the refrigerant (1) stored in the compressor (1) ( 7) increase, surely prevent the circulating refrigerant flow rate from decreasing, and
The refrigerating machine oil can be prevented from staying in the compressor (6), and the oil can be returned to the compressor (1). In the above embodiment, the flow velocity meter is used as the coolant flow velocity detecting means, but a coolant flow meter may be used.

Example 2. 4 to 9 show the second embodiment, FIG. 4 is a configuration diagram, and FIGS. 5 to 7 show the relationship between the condenser inlet refrigerant flow rate with respect to the condenser refrigerant temperature and the evaporator refrigerant temperature with respect to each compressor intake gas temperature. 8 is a block diagram of the control unit, and FIG. 9 is a flow chart for explaining the compressor cooling fan control operation.

In the figure, (1) is a compressor, (2) is a condenser,
(3) is a capillary tube which is a pressure reducing device, (4) is an evaporator, (5) is a header, (6) is piping, (7) is refrigerating machine oil, (8) is a refrigeration cycle, and (9) is a compressor. A cooling fan, (10) a fan motor, (12) a refrigerator control unit, (13) a compressor cooling fan control means, (14) an internal temperature sensor, and (15) a microcomputer. This is the same as the first embodiment shown in FIGS.

(6b) is a compressor suction pipe, (16) is a suction pipe temperature sensor which is a suction refrigerant temperature detecting means for detecting the refrigerant temperature in the compressor suction pipe (6b), and (17) is a condenser (2 ) Is a condenser temperature sensor is a condenser refrigerant temperature detection means for detecting the refrigerant temperature, (18) is an evaporator temperature sensor is an evaporator refrigerant temperature means for detecting the refrigerant temperature in the evaporator (4) . Also,
Also in this embodiment, HFC-134a is used as the refrigerant and hard alkylbenzene oil is used as the refrigerating machine oil (7).

5 to 7, the numerical values written above each plotted point are the condenser temperature T _e and the evaporator refrigerant temperature T _c at that point, and the suction refrigerant temperature is −10 ° C. (see FIG. 5),
The measured values of the refrigerant flow velocity value U _{g at} the inlet of the condenser at 30 ° C. (FIG. 6) and 40 ° C. (FIG. 7) are indicated by the numerical values in parentheses below the refrigerant flow velocity value U _g and the above (1). The ratio U _g / U _g 'of the zero penetration flow velocity value U _g ' calculated from the equation is shown, respectively. A straight line A in the figure is a line connecting points where U _g / U _g '= 1.2 (margin of 20%). It is shown that refrigerating machine oil does not stay in the region above the straight line A and refrigerating machine oil stays in the region below the straight line. These data are read in advance in the microcomputer (15).

Next, the control operation of the compressor cooling fan of this embodiment will be described with reference to the flow chart of FIG. First, in step (21), the detected temperature of the inside temperature sensor (14) is taken in, and in step (22) this detected temperature is compared with a preset set value for the inside temperature, and the detected value is set. If it is lower than the value, proceed to step (23) to stop the compressor (1), stop the fan motor (10) at step (24), and step (22) if the detected value is higher than the set value. Proceed to 25) to operate the compressor (1).

At the time of operating the compressor (1), in the step (30), the detection values of the suction pipe temperature sensor (16), the condenser temperature sensor (17) and the evaporator temperature sensor (18) are fetched, and the step (31) Then, based on these detected values, the refrigerant flow velocity value U _g is calculated from the data of FIGS. 5 to 7 previously read in the microcomputer (15), and this value is 1.2 of the zero penetration flow velocity value U _g '. Refrigerant flow velocity value U calculated by comparing with set value 1.2U _{g
If g} is equal to or greater than the set value 1.2 U _g '(within the set temperature range), proceed to step (28) to continue the operation of the fan motor (10), and if it is below the set value (set temperature). Out of range) go to step (29)
0) is stopped.

As described above, in this embodiment, the detected values from the temperature sensors (16), (17) and (18) of the suction pipe, the condenser, and the evaporator are fetched, compared with the refrigerating machine oil retention condition, and accumulated. If the condition is not satisfied, the fan motor (10) is driven in synchronization with the operation of the compressor (1), and if the condition is stagnant, the fan motor (10) is not driven and the compressor (1) is overloaded. No cooling is performed, and the same effect as that of the first embodiment is obtained.

Example 3. 10 to 12 show the third embodiment.
FIG. 10 is a block diagram of the control unit, FIG. 11 is a flow chart for explaining the compressor cooling fan control operation, and FIG. 12 is an experimentally obtained relationship between the condenser refrigerant temperature and the evaporator refrigerant temperature with respect to the outside air temperature. It is a figure.

In the figure, (1) is a compressor, (10) is a fan motor, (14) is an internal temperature sensor, (15) is a microcomputer, and (19).
Is an outside air temperature sensor which is an outside air temperature detecting means for detecting the outside air temperature, and is installed in a space for accommodating the base of the control unit (12) of the refrigerator. Also in this embodiment, HFC is used as the refrigerant.
-134a, hard alkylbenzene oil is used as the refrigerating machine oil (7).

Next, the control operation of the compressor cooling fan will be described with reference to the flowchart of FIG. First, the step
In (21), take in the temperature detected by the internal temperature sensor (14),
In step (22), this detected temperature is compared with a predetermined set value for the preset internal temperature, and if the detected value is lower than the set value, the process proceeds to step (23) to stop the compressor (1), The fan motor (10) is also stopped in step (24), and if the detected value is higher than the set value in step (22), the process proceeds to step (25) to operate the compressor (1).

During operation of the compressor (1), the detected value of the outside air temperature sensor (19) is taken in at step (33), and this detected value and a predetermined set value for outside air temperature are set at step (34). Compare, if the detected value is equal to or more than the set value, proceed to step (28) to continue the operation of the fan motor (10) .If the detected value is less than the set value, proceed to the step. Proceed to (29) and stop the fan motor (10).

The refrigerant flow velocity in the condenser inlet pipe (6a) satisfies a zero penetration flow velocity or more as a predetermined set value for the outside air temperature to be compared with the detection value of the outside air temperature sensor (19). Use the outside temperature. FIG. 12 shows the experimental data for obtaining this set value, and the outside air temperature of the two refrigerators was −20 ° C., −15 ° C., −1.
The condenser temperature T _e and the evaporator refrigerant temperature T _c at 1 ° C., 30 ° C. and 50 ° C. are plotted, and in the figure, a straight line B indicates a suction refrigerant temperature of 50 ° C. and a C indicates a suction refrigerant temperature of −. 15
When the temperature is ℃, the ratio U _g / U _g '= 1.2 (20) of the refrigerant flow rate U _g of the condenser inlet pipe (6a) and the zero penetration flow rate U _g '
% Margin) is a line that connects points.

It is shown that the refrigerating machine oil does not stay in the region above the straight lines B and C, and the refrigerating machine oil stays in the region below the straight line. From the experimental data, when the outside air temperature is −10 ° C. or lower, the refrigerating machine oil is very likely to stay. Therefore, the set value for the outside air temperature of the medium-sized refrigerator is set to about 0.0 ° C in consideration of safety.

As described above, in this embodiment, the detected value from the outside air temperature sensor (9) is fetched and compared with the outside air temperature condition in which refrigerating machine oil does not stay. If this condition is satisfied, the compressor (1) The fan motor (10) is driven in synchronism with the operation of, and the fan motor (10) is not driven under the condition of staying so as not to excessively cool the compressor (1). The same effect as that of the first embodiment is achieved. further,
As the outside air temperature sensor, the existing one installed in the conventional refrigerator can be used for controlling the heater for preventing the subcooling in the refrigerator, etc., so that the above effect can be obtained at a lower cost.

[0051]

As described above, according to the first aspect of the present invention, the drive of the compressor cooling fan is stopped when the refrigerant flow velocity in the inlet pipe of the condenser becomes a predetermined value or less. Therefore, according to the invention of claim 2, when the refrigerant flow velocity in the inlet pipe of the condenser becomes equal to or lower than the preset zero penetration flow velocity value of the inlet pipe of the condenser, the compressor cooling fan is cooled. Since the drive is stopped, overcooling of the compressor is prevented, refrigerating machine oil is prevented from staying in the pipes, oil returns to the compressor well, and a highly reliable refrigerator can be obtained. . Further, since the flow velocity of the refrigerant in the inlet pipe of the condenser is directly measured, the above-mentioned retention suppressing condition can be obtained with high accuracy, and the effect is further enhanced.

According to the invention of claim 3 of the present invention,
When the refrigerant temperature in the suction pipe of the compressor, the refrigerant temperature in the condenser and the refrigerant temperature in the evaporator are out of the preset temperature range, the driving of the compressor cooling fan is stopped, Overcooling of the compressor is prevented, refrigerating machine oil is prevented from staying in the pipes, oil returns to the compressor well, and an inexpensive temperature sensor is used without using an expensive refrigerant current meter. Since it can be used, there is an effect that an inexpensive and highly reliable refrigerator can be obtained.

According to the invention of claim 4 of the present invention,
When the outside air temperature is out of the preset temperature range, the compressor cooling fan is stopped, so the compressor is prevented from overcooling, and refrigerating machine oil is prevented from accumulating in the piping. The oil return to the machine is good, and the existing outside air temperature sensor that is commonly installed to prevent overcooling of the inside of the refrigerator can be used, so a cheaper and more reliable refrigerator can be obtained. effective.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a control unit according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a compressor cooling fan control operation according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a second embodiment of the present invention.

FIG. 5 is a diagram showing a condition for retaining refrigerating machine oil in a condenser inlet pipe of a refrigerator.

FIG. 6 is a diagram showing a condition for retaining refrigerating machine oil in a condenser inlet pipe of a refrigerator.

FIG. 7 is a diagram showing a condition for retaining refrigerating machine oil in a condenser inlet pipe of a refrigerator.

FIG. 8 is a block diagram of a control unit according to a second embodiment of the present invention.

FIG. 9 is a flowchart illustrating a compressor cooling fan control operation according to the third embodiment of the present invention.

FIG. 10 is a block diagram of a control unit according to the first embodiment of the present invention.

FIG. 11 is a flowchart illustrating a compressor cooling fan control operation according to the first embodiment of the present invention.

FIG. 12 is a diagram obtained by experimentally determining the relationship between the condenser refrigerant temperature and the evaporator refrigerant temperature with respect to the outside air temperature.

FIG. 13 is a refrigeration circuit diagram showing an example of a refrigeration cycle of a conventional refrigerator.

FIG. 14 is a diagram illustrating a state of refrigerant gas rising in a refrigerant pipe and refrigerating machine oil pushed by the refrigerant gas.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Decompression device (capillary tube) 4 Evaporator 6 Pipe 6a Condenser inlet pipe 6b Compressor suction pipe 7 Refrigerator oil 8 Refrigeration cycle 9 Compressor cooling fan 11 Refrigerant flow velocity detection means (refrigerant flow meter) 13 Compressor Cooling Fan Control Means 16 Intake Refrigerant Temperature Detection Means (Intake Pipe Temperature Sensor) 17 Condenser Refrigerant Temperature Detection Means (Condenser Temperature Sensor) 18 Evaporator Refrigerant Temperature Detection Means (Evaporator Temperature Sensor) 19 Outside Air Temperature Detection Means (outside air temperature sensor)

Claims (4)

[Claims] 1. A refrigeration cycle having a compressor, a condenser, a decompression device, an evaporator, and pipes connecting them, using a refrigerant and refrigerating machine oil having poor mutual solubility, and a compressor for cooling the compressor. In a refrigerator equipped with a cooling fan, a refrigerant flow velocity detecting means for detecting the refrigerant flow velocity in the inlet pipe of the condenser, and a compressor cooling fan when the detection value of the refrigerant flow velocity detecting means is below a predetermined value. And a compressor cooling fan control means for stopping the driving of the refrigerator. 2. A refrigeration cycle having a compressor, a condenser, a decompression device, an evaporator, and pipes connecting them, and using a refrigerant and refrigerating machine oil having poor mutual solubility, and a compressor for cooling the compressor. In a refrigerator equipped with a cooling fan, a refrigerant flow velocity detecting means for detecting the refrigerant flow velocity in the inlet pipe of the condenser, and the detection value of the refrigerant flow velocity detecting means is a preset inlet pipe of the condenser. A compressor cooling fan control means for stopping the driving of the compressor cooling fan when the flow rate is equal to or less than the zero penetration flow velocity value. 3. A refrigeration cycle having a compressor, a condenser, a pressure reducing device, an evaporator, and pipes connecting these, and using a refrigerant and refrigerating machine oil having poor mutual solubility, and a compressor for cooling the compressor. In a refrigerator equipped with a cooling fan, a suction refrigerant temperature detecting means for detecting a refrigerant temperature in a suction pipe of the compressor, a condenser refrigerant temperature detecting means for detecting a refrigerant temperature in the condenser, and the evaporation. Evaporator refrigerant temperature detecting means for detecting the refrigerant temperature in the condenser, the detection value by these temperature detecting means, the refrigerant flow velocity in the inlet pipe of the condenser is equal to or more than zero penetration flow velocity of the inlet pipe, preset And a compressor cooling fan control means for stopping the driving of the compressor cooling fan when the temperature is out of the specified temperature range. 4. A refrigeration cycle having a compressor, a condenser, a decompression device, an evaporator, and pipes connecting them, and using a refrigerant and refrigerating machine oil having poor mutual solubility, and a compressor for cooling the compressor. In a refrigerator equipped with a cooling fan, the outside air temperature detecting means for detecting the outside air temperature, and the value detected by this outside air temperature detecting means is such that the refrigerant flow velocity in the inlet pipe of the condenser is equal to or higher than the zero penetration flow velocity in the inlet pipe. And a compressor cooling fan control means for stopping the drive of the compressor cooling fan when the temperature is outside a preset temperature range that satisfies the above condition.