JPH0536699B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a refrigeration system used in a refrigerator, a storage case, an air conditioner, etc., and particularly relates to a refrigeration system using a rotary compressor as a compressor, which generates high pressure inside a closed container.

Conventional Structure and Problems There is a refrigeration system of this type that is used in, for example, a refrigerator, as shown in FIG. In this diagram 1
is a rotary compressor, 2 is a capacitor, 3 is a rotary compressor,
is a solenoid valve, 4 is a capillary tube which is a pressure reducer, 5 is an evaporator, 6 is a check valve, and solenoid valve 3 is a rotary valve operated by a thermostat (not shown) that opens and closes by sensing the temperature inside the refrigerator. It turns ON and OFF in synchronization with the compressor 1, and opens the flow path when ON and closes the flow path when OFF. As is well known, this type of rotary compressor 1 is of a high-pressure container type, and contains refrigerating machine oil 7 in which a refrigerant is dissolved in a container 8.

As is well known in this type of refrigeration system, during operation, the solenoid valve 3 closes and the check valve 6 also closes, so the inside of the container 8 is maintained at high pressure and high temperature, and the refrigeration oil 7 is constantly exposed to high pressure and high temperature.

Furthermore, since the conditions under which this type of refrigeration system is operated range from low outside temperatures to high outside temperatures, both the temperature and pressure within the container 8 of the rotary compressor 1 fluctuate greatly.

The amount of refrigerating machine oil 8 dissolved in the refrigerant has characteristics as shown in FIG. In other words, at the same pressure, the lower the temperature, the greater the amount of refrigerant dissolved, and at the same temperature, the higher the pressure, the greater the amount of refrigerant dissolved. To give an example, the amount dissolved is 35% when the pressure is 8 kg/cm ² G, and 21% when the pressure is 5 kg/cm ² G. It is shown by the broken line B in the figure. Therefore, the characteristics of the amount of dissolution depending on the outside temperature are as shown in FIG. In other words, if you compare the outside temperature of 15℃ and 30℃, there will be a difference in the amount of melting of 70g - 40g = 30g, and if the total amount of refrigerant sealed is, for example, 200g, this will correspond to 15% of that amount. For example, if the amount of refrigerant charged is appropriate at an outside temperature of 30°C, the first drawback is that 30g of refrigerant is insufficient at an outside temperature of 15°C.

In addition, since the restriction resistance of the capillary tube 4 is fixed, it is normally set to be appropriate at high outside temperatures, and has the second drawback that the resistance tends to become excessive at low outside temperatures. Was.

Further, the first and second drawbacks described above are caused by each other.

OBJECTS OF THE INVENTION In view of the above points, the present invention aims to provide a refrigeration system that can secure the amount of refrigerant circulation at low outside temperatures and save power.

Composition of the Invention In order to achieve the above object, the refrigeration system according to the present invention includes an on-off valve device that opens and closes due to sudden pressure changes caused by starting and stopping the compressor, and an opening degree that is controlled by the difference in pressure during operation depending on the outside air temperature. A flow rate control valve having a regulating valve device is interposed within the device.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, reference numeral 10 denotes a refrigeration system according to the present invention, which is used as a refrigeration cycle of a refrigerator (not shown). A rotary compressor 11 is composed of a sealed container 12, a mechanical part 13, an electric motor 14, and a refrigerating machine oil 15. 16 is a capacitor,
17 is a flow control valve, 18 is a capillary tube,
Reference numeral 19 is an evaporator, 20 is a check valve, and 21 is a suction pipe of the rotary compressor 11, which are successively connected in an annular manner.

Next, the flow control valve 17 will be explained. 22 is the upper casing, 23 is the lower casing, both 22,
23 are brought into close contact with each other to form the flow control valve main body 17. A diaphragm 24 is interposed between the casings 22 and 23 and divides the inside of the main body 17 into two chambers.
The upper chamber is configured as a valve chamber 25, and the lower chamber is configured as a pressure sensitive chamber 26. A pressure equalizing pipe 27 communicates the pressure sensitive chamber 26 with the suction pipe 21 between the rotary compressor 11 and the check valve 20. 28 is a bias spring interposed between the diaphragm 24 and the lower casing 23 in the pressure sensitive chamber 26, and is used to set the pressure displacement of the diaphragm 24 to a predetermined value; A stopper is provided in the bias spring 28 between the diaphragms 24 and 28 to restrict excessive movement of the diaphragm 24.

An on-off valve device 30 is configured within the valve chamber 25 . The on-off valve device 30 includes a circular port 31 passing through the center, a valve seat 32 formed on the lower surface of the port 31, and a block 35 that forms a holding part 34 that holds the upper end of a spring 33 and is attached to the upper casing 22. , a ball valve 36 that contacts the valve seat 32, a holder 37 that contacts the diaphragm 24 that adhesively holds the ball valve 36, and a block 35.
and the spring 33 interposed between the holder 37.

The upper casing 22 has an inlet pipe 38 from the condenser 16 that is open to the valve chamber 25, and an outlet pipe 40 that extends from the upper part of the block 35, has a regulating valve device 39 inside, and leads to the capillary tube 18. ing.

This regulating valve device 39 includes a taper port 44 formed in the port 31 on the opposite side of the valve seat 32 of the block 35, a retainer 42 formed on the downstream side of the taper port 44, and a connection between the retainer 42 and the taper port 44. The needle 43 is formed into a tapered shape and moves between the needles 43 and the retainer 42 to adjust the distance from the taper port, and a biasing spring is provided between the needle 43 and the retainer 42.

The retainer 42 forms a through hole 45 in the center,
An engaging portion 47 in which an outer circumferential recess 46 is formed in the outlet pipe 40
, and holds one end of the biasing spring 41. The other end of the biasing spring 41 is in contact with the large diameter portion of the needle 43 so as to press the needle 43 against the taper port 44 . A connecting rod 48 having a substantially triangular cross section is brought into contact with a small diameter portion of the needle 43 facing the tapered port 44 .

The connecting rod 48 is slidably provided within the port 31, and its lower end abuts the ball valve 36. That is, the needle 43 is substantially connected to the ball valve 36 via the connecting rod 48 by the biasing spring 41.

Next, the relationship between the on-off valve device 30, the bias spring 28, the stopper 29, and the regulating valve device 39 will be explained.

The spring 33 is used to ensure that the holder 37 holding the ball valve 36 follows the displacement of the diaphragm 24, and the combined force of the bias spring 28, spring 33, and biasing spring 41 causes the opening/closing valve device 30 to maintain a predetermined pressure difference. It is set to open at Po. In this embodiment, this pressure difference Po is set to 2
Kg/cm ² is installed. Therefore, the closed container 12,
Condenser 16 and valve chamber 25 of flow control valve 17
pressure equalizing pipe 2 connected to the suction pipe 21 between the check valve 20 and the rotary compressor 11
When the difference in pressure between the pressure in the pressure sensitive chamber 26 communicated at 7, that is, the pressure difference between the upper and lower surfaces of the diaphragm 24 is 2 kg/cm ² or more, the force due to the pressure difference acting on the diaphragm 24 is applied to the bias spring 28, the spring 33, and the attachment. The force is greater than the total force of the force spring 41, and the diaphragm 24 is displaced downward in the figure, and the holder 37 and ball valve 36, which follow the displacement of the diaphragm 24, are also displaced downward, and the opening/closing valve device 30 is opened. . In addition, the ball valve 36 and the connecting rod 4
The needle 43, which is substantially joined via the needle 8, is also displaced downward.

Therefore, the flow path formed by the needle 43 and the taper port 44 of the regulating valve device 39 is connected to the diaphragm 2.
The larger the displacement of 4, the narrower it becomes.

In addition, regarding the relationship between the overall spring constant of the bias spring 28, spring 33, and biasing spring 41 and the stopper 29, when the pressure difference acting on the diaphragm 24 is equal to or greater than the set value _P1 , the diaphragm 24 is applied to the stopper 29. Designed to touch.
In this embodiment, this set value P ₁ is set to 8 kg/cm ² . Further, the regulating valve device 39 is designed so that even when the diaphragm 24 comes into contact with the stopper 29, the flow path formed by the needle 43 and the taper port 44 is secured.

The above pressure difference and the ball valve 36 of the on-off valve device 30
and the valve seat 32, the resistance _R2 of the flow path formed by the needle 43 and the taper port ₄₄ of the regulating valve device 39, and the total resistance R of both resistances R1 _{and R2} . has the relationship shown in FIG. That is, when the pressure difference is below a predetermined value (Po=2Kg/cm ² ), the on-off valve device 30 is closed, so the total resistance R becomes ∞, and the minimum resistance is reached at the point where it becomes slightly larger than 2Kg/cm ² . As the pressure difference further increases, the total resistance R gradually increases, and the total resistance R becomes constant above the set value (P ₁ =8 Kg/cm ² ). Therefore, the resistance of the capillary tube 18 of the refrigeration system 10 using the flow control valve 17 is designed to be smaller than the resistance Ro of the conventional capillary tube 4. This relationship is as shown in Figure 6, and the diaphragm 2
The pressure difference acting on 4 is a predetermined value (Po=2Kg/cm ² )
Below, the flow control valve 17 and the capillary tube 1
The combined resistance R of 8 is ∞, but the pressure difference is 2Kg/cm ²
When it becomes slightly larger, the resistance decreases rapidly and is much less than the resistance Ro of the conventional capillary tube 4. Compliant resistance R as pressure difference increases
Although the resistance increases, it is smaller than the resistance R _O of the conventional capillary tube 4. At the point where the pressure difference is the set value (P ₁ = 8Kg/cm ² ), the combined resistance R is the same as the resistance Ro of the conventional capillary tube 4,
For higher pressure differences it remains the same.

Next, the operation of the above configuration will be explained. During operation of the rotary compressor 11, the suction pipe 21
The pressure of
The pressure is also low. On the other hand, the airtight container 12, the condenser 16, and the valve chamber 25 communicating therewith through the inlet pipe 38 are at high pressure. Therefore, the diaphragm 24
High pressure acts on the top surface and low pressure acts on the bottom surface, and the acting force due to this pressure difference acts on the bias spring 28 and the spring 3.
3. Due to the overall force of the biasing spring 41, the force is increased and is displaced downward. In response to this displacement of the diaphragm 24, the holder 37 and the ball valve 36 are also displaced downward by the spring 33, and the on-off valve device 30 is opened. Further, in the regulating valve device 39, the flow path between the needle 43 and the taper port 44 changes due to the pressure difference, but the refrigerant flows between the inlet pipe 38 → the valve chamber 25 → the circular port 31 and the triangular connecting rod 48. The liquid flows from the flow path to the flow path of the needle 43 and taper port 44 to the outlet pipe 40 to the capillary tube 18, and a normal cooling operation is performed.

While the rotary compressor 11 is in operation, the mechanical part 13 is securely mechanically sealed by the refrigerating machine oil 15, but the rotary compressor 1
1 stops, the mechanical seal is broken and the high pressure gas inside the closed container 12 flows back into the suction pipe 21.
This backflow causes the check valve 20 to close, and the suction pipe 21
The pressure inside rises rapidly and balances out with the high pressure side. At the same time, the pressure within the pipe pressure chamber 26 communicated with the pressure equalizing pipe 27 also rises rapidly, the pressure difference acting on the diaphragm 24 decreases, and the combined force of the bias spring 28, spring 33, and biasing spring 41 forces the diaphragm 24 upward. The on-off valve device 30 is displaced to
is closed, preventing high-pressure refrigerant from flowing into the low-pressure evaporator 19, and maintains the same pressure state during stoppage as during operation.

When the rotary compressor 11 is restarted from this state, the pressure inside the suction pipe 21 and the pressure sensitive chamber 26 communicated with it through the pressure equalization pipe 27 becomes low, and the pressure difference acting on the diaphragm 24 opens and closes Valve device 30 is opened. At this time, since the pressure state continues to be stable even during the stoppage, normal cooling operation is performed from the time of startup.

Note that after the rotary compressor 11 is stopped, the pressures in the valve chamber 25 and the pressure-sensitive chamber 26 are not balanced instantly, and it takes several minutes until they are completely balanced. Therefore, the opening/closing pressure difference of the opening/closing valve device 30 is set to 0.
Kg/cm ² , refrigerant flows into the evaporator 19 after stopping, reducing the power saving effect.

In order to prevent this decrease, after stopping the valve chamber 25
It is necessary to close the on-off valve device 30 when the pressure difference in the pressure sensitive chamber 26 is large. In addition, in general refrigerators, etc., it is necessary to guarantee cooling operation even at extremely low outside temperatures of -15°C, so the on-off valve device 30 does not open during operation even at this low outside temperature of -15°C. There must be. Therefore, in the embodiment of the present invention, the on-off valve device 30 is operated at a pressure difference of 2.5 kg/cm ² when the outside temperature is -15°C.
In order to open the circuit, the predetermined value Po is set to 2 kg/cm 2 which is less than 2.5 kg/cm ² of the pressure difference between the valve chamber 25 and the pressure sensitive chamber ²⁶ at an outside temperature of -15°C.

Next, the operation of the regulating valve device 39 will be described in detail.
As an example, we will explain outside temperatures of 30°C and 15°C. At an outside temperature of 30°C, the pressure inside the closed container 12, condenser 16, and valve chamber 25 during operation is approximately 9 kg/cm ² G, the same as in a general refrigerator or other refrigeration equipment, and the suction pipe 21, evaporator 19, and pressure sensitive chamber 26. The pressure inside is approximately 0Kg/
cm ² G, and the pressure difference acting on the diaphragm 24 is 9 Kg/cm ² which is larger than the set value (P ₁ = 8 Kg/cm ² ).
becomes. Therefore, the diaphragm 24 is connected to the stopper 2
9, the resistance of the regulating valve device 39 is fixed at the maximum position, and the combined resistance of the flow regulating valve 17 and the capillary tube 18 is the same as the resistance of the conventional capillary tube 4. The same cooling is performed.

Next, we will explain the outside temperature of 15°C.

At an outside temperature of 15°C, the pressure of the refrigerant is lower than when it is at 30°C, so the pressure inside the sealed container 12, condenser 16, and valve chamber 25 is approximately 6 kg/cm ² G, similar to a freezing device such as a general refrigerator. The internal pressures of the evaporator 19, suction pipe 21, and pressure sensitive chamber 26 are approximately -0.1 Kg/cm ² G, which is higher than that of a freezing device such as a general refrigerator. Therefore, the pressure difference acting on the diaphragm 24 is 6.1 kg/cm ² . This pressure difference is the set value (P ₁ =
8 kg/cm ² ), the resistance of the regulating valve device 39 is smaller than when the outside temperature is 30°C, so the combined resistance of the flow regulating valve 17 and the capillary tube 18 is smaller than that of the conventional capillary tube 4. It is smaller than the resistance. Therefore, the low pressure of a general refrigerator or other refrigeration device at an outside temperature of 15℃ is approximately -0.3Kg/cm ²
-0.1Kg/cm ² G, which is higher than G.

Refrigerating machine oil 15 in a sealed container 12 at an outside temperature of 15°C
The amount of refrigerant dissolved in the refrigerant is larger than that at an outside temperature of 30°C, similar to the conventional refrigeration system, but since the resistance of the regulating valve device 39 is small and the low pressure during operation is high, the rotary compressor 11 Suction pipe 2
The specific volume of the refrigerant in the rotary compressor 11 decreases, and the amount of refrigerant compressed and circulated per rotation of the mechanical part 13 of the rotary compressor 11 increases, thereby preventing gas starvation operation.

Therefore, refrigerant dissolution into the refrigerating machine oil 15 increases,
Further, as the outside temperature becomes lower and the throttle resistance increases and gas starvation operation increases, the pressure difference acting on the diaphragm 24 decreases and the opening degree of the regulating valve device 39 increases.
This ensures a sufficient amount of refrigerant circulation even at low outside temperatures.
This can prevent gas shortage operation. The flow control valve 17 has an on-off valve device 30 and a regulating valve device 39 in the same main body 17, and the check valve 20 has a pressure sensitive chamber 26 and a condenser 16 communicating with the suction pipe 21 on the downstream side. Since the diaphragm 24, which is displaced by the pressure difference between the communicating valve chambers 25, operates the opening/closing valve device 30 and the regulating valve device 39, the configuration of the refrigeration device 10 is simple, and the number of welded parts such as piping is minimized. I am able to do that.

Furthermore, the operating pressure difference between the diaphragm 24 and the suction pipe 2 downstream of the condenser 16 and the check valve 20 is
Since the pressure difference between the compressor 11 and Therefore, it is possible to open and close the on-off valve device 30 in reliable response to the operation and stop of the compressor 11. Further, since the pressure difference during operation is the pressure difference between high and low pressure partners, it is possible to adjust the regulating valve device 39 much more accurately than by using a pressure difference between high pressure and atmospheric pressure.

Effects of the Invention As is clear from the above explanation, the refrigeration system according to the present invention includes an on-off valve device that opens due to a pressure change when the compressor is started and closes due to a pressure change when the compressor is stopped, and a shut-off valve device that responds to the pressure during compressor operation. Since the valve has a flow control valve equipped with a regulating valve device that controls the opening degree of the flow path, it can perform the same action as a conventional solenoid valve without requiring electrical input by using an on-off valve device. , the same pressure state as during operation is maintained even when stopped, enabling the most efficient cooling operation when operation is stable immediately after startup.

Furthermore, the opening of the flow path can be automatically adjusted to ensure an appropriate amount of refrigerant circulation even at low outside temperatures, which would conventionally result in gas starvation. Since it enables cooling operation, it enables large power savings, especially in refrigeration equipment such as refrigerators where outside temperature changes are large.

[Brief explanation of the drawing]

Figure 1 is a system diagram of a conventional refrigeration system, Figure 2 is a characteristic diagram of refrigerant dissolution in normal refrigeration oil, Figure 3 is a diagram of changes in the amount of refrigerant dissolved in refrigeration oil in the refrigeration equipment at outside temperature, and Figure 4 is a diagram of the change in outside temperature. Figure 5 is a system diagram of a refrigeration system according to an embodiment of the present invention, Figure 5 is a flow path resistance characteristic diagram of a flow control valve, Figure 6 is a pressure reducer resistance characteristic of the refrigeration system of Figure 1, and Figure 4 is a diagram of the pressure reducer resistance of the refrigeration system. The figures are shown respectively. 11... Rotary compressor, 16... Condenser, 17... Flow rate adjustment valve, 18... Capillary tube (pressure reducer), 19... Evaporator,
20...Check valve, 24...Diaphragm, 25...
... Valve chamber, 26 ... Pressure sensitive chamber, 37 ... Pressure equalization pipe, 30
...Opening/closing valve device, 32...Valve seat, 36...Valve, 3
9... Regulating valve device, 43... Needle, 44...
Tapered port.

Claims (1)

[Claims] 1 A compressor 11, a condenser 16, a flow control valve 17, a pressure reducer 18, an evaporator 19, and a check valve 20 are sequentially connected in an annular manner.
A valve chamber 25 and a pressure sensitive chamber 2 are formed inside by a diaphragm 24.
6 to form an on-off valve device 30 and a regulating valve device 39.
and a pressure equalizing pipe 27 connected between the pressure sensitive chamber 26, the compressor 11 and the check valve 20, and the opening/closing valve device 30 is connected to the valve seat 32.
and a valve 36 that moves between a position in which it comes into contact with the valve seat 32 and a position in which it does not come into contact with the valve seat 32 by the movement of the diaphragm 24, and the regulating valve device 39 is arranged downstream of the on-off valve device 30, and diaphragm 2
4, and a connecting rod 48 that transmits the movement of the diaphragm 24 to the needle 43 and moves the needle 43 in the direction of increasing the opening area at high outside temperatures.
A refrigeration device formed from.