JPS5896954A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compact refrigeration device such as a refrigerator that uses a high-pressure container-type hermetic compressor.

In small refrigeration equipment that uses a hermetic compressor (hereinafter referred to as a rotary compressor) of a high-pressure container type, such as a general rotary compressor, the inside of the hermetic container is on the high pressure side, so it is a low-pressure container type compressor like a general reciprocating compressor. Compared to a hermetic compressor (hereinafter referred to as a reciprocating compressor), the amount of refrigerant sealed in the refrigeration equipment increases significantly.As an example, in a popular refrigerator-freezer, the amount of refrigerant packed in a reciprocating type is about 160 g, Approximately 250 for rotary type
g, which is a large increase of more than 50%. Of this 100g increase in refrigerant, some of it is converted into high-temperature, high-pressure superheat gas, and the rest is dissolved in the refrigeration machine oil and remains in the sealed container. Due to this function, when the refrigeration equipment is stopped, it is in a superheated gas state, and what is dissolved in the refrigeration oil is vaporized and heated in the high-temperature part of the sealed container, becoming a high-temperature, high-pressure superheated gas that flows into the evaporator.

As the first flow path, it flows from the closed container to the condenser to the capillary tube to the evaporator, and as the heat is dissipated by the condenser, it flows in as superheated gas at room temperature, but the temperature difference with the evaporator is very large, so the evaporator This had the disadvantage of heating up the air, resulting in a large heat load. In addition, as a second flow path, the superheated gas flows at high temperature and high pressure into the evaporator from the closed container to the cylinder chamber of the compression element to the suction line to the evaporator and heats the evaporator, which also has the drawback of causing a large heat load. The high-temperature, high-pressure gas in the closed container flows into the cylinder chamber because the cylinder chamber of existing rotary compressors is configured with a mechanical seal using metal surface contact. That is, in the refrigeration system using this rotary compressor, a large amount of high-temperature, high-pressure superheat gas flows into the evaporator, resulting in a large heat load. Therefore, when a rotary compressor, which is about 20% more efficient than a conventional reciprocating compressor, is actually attached to a refrigerator-freezer and measured in a JIS C96o7 electric refrigerator and freezer power consumption test, the effectiveness is significantly reduced. , the amount of electricity saved was only about 6%. In order to increase the amount of reduction in power consumption equivalent to the efficiency improvement of the rotary compressor, it is necessary to prevent a large amount of superheat gas from flowing into the evaporator from the first and second flow paths. The method currently used in some cases is to improve the second flow path, which is to install check pulp in the suction line of the refrigeration equipment, but since the first flow path has not been improved, its effectiveness is limited. The reduction in power consumption is only about 5%, which is a total effect of about 10 inches. In addition, a possible method for improving the first flow path is to install a solenoid valve at the condenser outlet and open and close it in conjunction with the operation of the refrigeration equipment, but solenoid valves are expensive and generate noise during operation. Furthermore, a control circuit for the solenoid valve is required, which complicates the electric circuit, and the electric circuit itself consumes electric power.

In view of the above drawbacks, the present invention aims to provide a refrigeration system that is inexpensive, does not require electrical control, is quiet, and has an efficiency equal to or higher than that of a rotary compressor alone. The aim is to provide refrigeration equipment.

An embodiment of the present invention will be described below. Reference numeral 1 denotes a high-pressure container type hermetic compressor (hereinafter referred to as a rotary compressor) such as a rotary compressor, which is composed of a hermetic container 2, a compression element 3, and an electric element (not shown). Further, this rotary compressor 1 does not have an internal check valve that closes the low pressure side when the compressor is stopped. and,
Refrigeration equipment c, mouth → tally compressor 1, condenser 4
, a high-pressure circuit 5a of a fluid control valve 6 for a refrigeration system, a pressure reducer 6 such as a capillary tube 6 (hereinafter referred to as capillary tube 6), an evaporator 7, a check valve 8, a suction line 9, and a rotary compressor 1 are sequentially connected in an annular manner. It consists of The fluid control valve 6 has a high pressure side valve device 5A including a high pressure circuit 6a and a low pressure circuit 5b, and the low pressure circuit 6b is connected to the suction line 9. The fluid control valves 6 each include an independent substantially hollow cylindrical high-pressure side casing 10;
This also forms an outer shell 12 with a substantially hollow cylindrical low pressure side casing 11, and both 9 and 1o are integrated to maintain airtightness. Reference numeral 13 denotes a pressure-responsive element (hereinafter referred to as bellows) which partitions the outer shell 12 into a high-pressure circuit 5a and a low-pressure circuit 6b and expands and contracts in response to the pressure of the two circuits. A coil spring 14 is provided at the center of the lower end of the bellows 13 to bias the bellows 13 upward in the figure. Reference numeral 15 denotes an adjustment member (hereinafter referred to as a retainer) that holds the lower end of the coil spring 14, and restricts excessive movement of the bellows 13 and prevents damage. This retainer 16 has a plurality of small holes 16a for the bellows 13 to correctly sense the pressure of the low pressure circuit 6b.

15a... and screws 15b are provided on the outer periphery. This retainer 15 is screwed into a threaded portion 10a provided on the inner surface of the high-pressure side casing 10, and after adjusting the biasing force of the coil spring 14 to a predetermined value, it is fixed by an appropriate method. On the other hand, the high pressure side casing 10 has an inlet pipe 10
A, an outlet pipe 10b, and a valve seat 10c, and a cylindrical plunger 16 is housed in the shaft so as to be slidable up and down. A high pressure valve 17 made of a ball valve is fixed to the center of the upper end of the plunger 16 by caulking, and is connected to the high pressure side valve device 5A.
is formed. A recess 15a is provided at the lower end of the plunger 16 for connecting the plunger 16 and the bellows 13, and the bellows 13 is connected and supported by sizing processing. Note that the sizing process is performed by providing a gap 16b for centripeting the high pressure valve 17 to the valve seat 10c. The low pressure side casing 11 also has an inlet pipe 11a1.

Next, the operation when the above fluid control valve is incorporated into a refrigeration system will be described. Figure 1 shows a state diagram when the refrigeration system is in operation.The high-pressure side of the refrigeration system is at normal high pressure, and the low-pressure side is also at normal low pressure, so the bellows 13 of the fluid control valve 5 is under high pressure. Due to the pressure difference between the circuit 5a and the low pressure circuit 5b, the coil spring 14 is pushed down and expanded until it hits the retainer 15. Therefore, the high pressure valve 17 has a bellows 13
Due to the sum of the pressure difference between the high pressure circuit 5a and the evaporator 7 and the biasing force of the coil spring 14, the valve seat 10c is pulled away by the plunger 16 integrally attached to the valve seat 10c, and the high pressure side valve device 6A is pulled away. is in an open state. On the other hand, the check valve 8 is in an open state due to the gas flow flowing in from the evaporator 7. Therefore, the refrigerant gas discharged from the rotary compressor 1 is transferred to the condenser 4, the high pressure circuit 5a of the fluid control valve 6, the capillary tube 6,
It flows without any problem to the evaporator 7, check valve 8, saxilane line 9, and rotary compressor 1 to perform the refrigeration action.

Next, the state in which the refrigeration system is stopped will be explained using FIG. 2. When the rotary compressor 1 is stopped, the high-temperature, high-pressure gas in the closed container 2 flows into the suction line 9 through the cylinder chamber (not shown) of the compression element 3, resulting in a reverse flow state, and therefore the check valve 8 becomes in a closed circuit state. As a result, superheat gas from the rotary compressor 1 is prevented from flowing backward into the evaporator 7. As more time passes, the fluid flows into the low pressure circuit 6b of the fluid control valve 6 connected to the suction line 9 (indicated by an arrow in the figure), so the pressure in the low pressure circuit 5b increases rapidly and becomes equal to the pressure in the high pressure circuit 6a. This is an approximation. When the pressures in both the circuits 5a and 5b become approximate, the biasing force of the coil spring 14 provided below the bellows 13 overcomes the force generated in the bellows 13 due to the pressure difference between the circuits sa and sb, and the plunger 16 is pushed up to move to the high pressure side. The valve device 6A is closed and prevents superheat gas from flowing into the evaporator 7 from the condenser 4.

Furthermore, the functions of the coil spring 14 that urges the bellows 13 upward and the retainer 15 that adjusts the urging force of the coil spring will be explained using the pressure change diagram of the refrigeration system shown in FIG. In the figure, the check valve 8 is closed at the same time as the rotary compressor 1 stops, and the pressure in the low pressure circuit 6b rapidly increases due to the superheat gas flowing back from the rotary compressor 1. At this time, the high pressure side valve device 5
A is still in an open state, and the capacitor 4 and high pressure side valve device 6
The pressure in the outlet pipe 10b of A drops equally and gradually. When a minute time t has elapsed after this stop, a force Ep (Ep
= ΔPxS), the biasing force FC of the coil spring 14 increases, the plunger 16 is pushed up, and the high pressure side valve device 5
A becomes a closed circuit state. From this point on, the refrigerant flowing into the high pressure circuit 5a stops, so the outlet pipe 10 of the high pressure side valve device 5A
The pressure at b drops rapidly. This pressure drop causes the high pressure valve 17 to be further attracted to the valve seat 10C, reducing leakage. Note that after the rotary compressor 1 stops, the high pressure side valve device 6
The minute time t required for A to close must be approximately 30 seconds or less. This period of 30 seconds or less depends on the size of the refrigeration system and the size of the rotary compressor 1. However, after the refrigeration system stops, it takes about 45 seconds to 1 degree for the liquid refrigerant to condense in the condenser 4 and flow into the cavity tube. Since normal refrigeration is performed, the high pressure side valve device 5A is
This is because it is sufficient to close the valve. For this purpose, it is necessary to make the minute time t as small as possible, and for this purpose, the high pressure side valve device 6A is closed when the pressure difference ΔP is large. However, if the differential pressure ΔP that closes the high pressure side valve device 6A is set too large, the difference between the pressure of the condenser 4 and the pressure of the evaporator 7 during operation is small when the temperature is low such as in winter, so the high pressure side valve device 5A
A sufficient pressure difference to open the valve cannot be obtained, and the high-pressure side valve device 6A remains closed regardless of whether the rotary compressor 1 is operating or not, resulting in a state in which refrigeration cannot be performed. The ideal setting value of the differential pressure ΔP in a household refrigerator-freezer is within a very small range of about 2±0.2ζ. Therefore, it is necessary to adjust the biasing force in response to manufacturing variations in the spring constant of the coil spring 14. Furthermore, when the refrigeration system is started, the pressure in the low circuit 6b instantly becomes low and the bellows 13
is pulled down, the high-pressure valve 17 integrated with the bellows 13 descends via the plunger 16, and the high-pressure side valve device 6A opens to perform a normal refrigeration action.

As described above, the refrigeration system of the present invention connects the high pressure side valve device including the high pressure circuit of the fluid control valve to the upstream side of a pressure reducer such as a capillary tube, connects the check valve to the downstream side of the evaporator, and The low pressure circuit of the control valve is connected to the downstream side of the check valve, and the high pressure side valve device opens when the pressure in the low circuit is low;
When the pressure is high, the valve closes in response to the pressure, so normal refrigerant circulation occurs when the refrigeration system is in operation, and when the refrigeration system is stopped, the check valve closes immediately and the pressure in the low pressure circuit is reduced. Since the high-pressure side valve device is closed during a short period of time when the liquid refrigerant is flowing out to the pressure reducing device, the superheated gas in the sealed container and condenser will not flow into the evaporator via the suction line and the pressure reducing device. prevent. Therefore, the power saving effect is greater than that of a system without a fluid control valve, and the efficiency of the refrigeration system can be improved commensurate with the efficiency improvement of the rotary compressor. It is also less expensive than those controlled by solenoid valves, does not require electric power to control, does not require an electrical control circuit, does not require extra electrical wiring, and operates smoothly, making it less noisy. It has the characteristics that it does not occur.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the refrigeration system of the present invention, FIG. 2 is a sectional view of the main part of a stopped fluid control valve corresponding to FIG. 1,
FIG. 3 is a pressure change diagram of the refrigeration system shown in FIG. 1. 1... Hermetic compressor, 4... Condenser, 6... Pressure reducer, 7... Evaporator, 8... Check valve, 9...Suction line, 5...Fluid control valve, 5b...Low pressure circuit, 5a...High pressure circuit, 6A...
High pressure side valve device, 13... Pressure responsive element, 16.
...adjustment member, 14...spring. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 4 Figure 2

Claims (1)

[Claims] It is equipped with a hermetic compressor in the form of a high-pressure container, a condenser, a pressure reducer, an evaporator, a check valve interposed therein, and a fluid control valve, the fluid control valve having a low-pressure circuit and a high-pressure circuit having a high-pressure side valve device. and a pressure-responsive element that partitions the high-pressure circuit and the low-pressure circuit and operates based on the difference in pressure applied both times, the high-pressure side valve device is connected to the pressure-responsive element, and the pressure-responsive element The high-pressure side valve device is biased in a direction to close by a spring supported via an adjustment member, and the low-pressure circuit communicates with the downstream side of the check valve, and the high-pressure circuit communicates with the upstream side of the pressure reducing device. Refrigeration equipment.