JPS62228838A - Refrigeration cycle - 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 [Object of the Invention (Industrial Field of Application) The present invention relates to a refrigeration cycle in which the pressures on the discharge port side and the suction port side of the compressor can be balanced after the compressor is stopped.

(Prior Art) A conventional general refrigeration cycle is constructed by connecting a condenser, a throttle device, and a cooler between a discharge port and a suction port of a compressor. In such a refrigeration cycle, the pressure difference between the discharge port and suction port during compressor operation does not reduce for a considerable period of time even after the compressor has stopped, resulting in an overload condition when the compressor is restarted. An excessive starting current will flow. Such problems can occur not only in reciprocating type compressors but also in rotary type compressors where the clearance between the housing and rotor is reduced in order to improve efficiency (those with a small amount of refrigerant backflow). .

Therefore, in order to reduce the load when starting the compressor, a communication passage is provided that communicates the discharge port side and the suction port side of the compressor, and a solenoid valve that is closed during compressor operation is installed in the middle of this communication passage. There is a compressor in which the solenoid valve is opened as soon as the compressor is stopped so that the pressures on the discharge port side and one suction port side of the compressor are balanced.

However, if a solenoid valve is used as the opening/closing valve of the communication passage, a control circuit for controlling power supply/disconnection to the solenoid valve is also required, resulting in an overall high cost. Moreover, since electric power must be supplied to the solenoid valve to open and close it, there is also the disadvantage that extra electric power that is not directly related to cooling (compressor operation) is consumed.

(Problems to be Solved by the Invention) As mentioned above, in the case where the communication passage is opened and closed by a solenoid valve so that the pressure can be balanced between the discharge port side and the suction port side when the compressor is stopped, the cost is generally high. get high,
Moreover, there is a drawback that the power consumption of the entire refrigeration cycle has not yet been sufficiently reduced.

The present invention is intended to solve the above-mentioned drawbacks, and its first object is to ensure pressure equilibrium between the discharge port side and the suction port side when the compressor is stopped, and to reduce manufacturing costs and power consumption. An object of the present invention is to provide a refrigeration cycle that can reduce the amount of refrigeration.

[Structure of the Invention] (Means for Solving the Problems) The refrigeration cycle of the present invention is provided with a casing between the discharge port of the compressor and the condenser, through which refrigerant from the discharge port flows, and A pressure-responsive body is provided so that the outlet formed in the casing and the suction port side of the compressor are communicated through a communication passage, and a closed space in which a heat-sensitive medium is enclosed is formed in the casing;
This pressure-responsive body is provided with a valve body that opens and closes the outlet.

(Function) When the compressor is in operation, the heat-sensitive medium is expanded by the heat of the refrigerant flowing in the casing, thereby displacing the pressure-responsive body so that the valve body closes the outlet of the casing. On the other hand, when the compressor is stopped, high-temperature refrigerant does not flow into the casing, so the temperature inside the casing decreases, and the concomitant contraction of the heat-sensitive medium causes the pressure-responsive body to be moved so that the valve element opens the outlet. By displacing the compressor by one amount, the pressure is balanced between the discharge port side and the suction/inlet side of the compressor through the communication passage.

In this case, since the driving source of the valve body is a heat-sensitive medium that expands and contracts depending on the presence or absence of refrigerant flow within the casing,
No control circuit or electric power is required to open and close the valve body.

(Example) Hereinafter, one example of the present invention will be described based on the drawings. Reference numeral 1 denotes a rotary type compressor, which has a condenser 2, a differential pressure valve 3, a capillary tube 4 serving as a throttle device, a cooler 5, and a check valve 6 connected in series between its discharge port 1a and suction port 1b. . 7 is a casing of a valve device 9 provided in a refrigerant passage 8a between the discharge port 1a of the compressor 1 and the condenser 2, and a refrigerant inlet 10 and a refrigerant outlet 11 formed in this casing 7 are connected to the refrigerant passage 8a. are doing. Further, an outlet 12 is formed in the upper part of the casing 7 in the drawing, and the outlet 12 and the discharge port lb side of the compressor 1 are connected through a communication passage 13.

In this case, the communication passage 13 has a capillary tube 14 whose outflow side end is connected to the refrigerant passage 8b between the reverse valve 6 and the suction port 1b of the compressor 1. A portion of the communication path 13 closer to the casing 7 than the capillary tube 14 is connected to the pressure introduction port 3a of the differential pressure valve 3 by a pressure outlet pipe 15. As a result, the pressure introduction port 3a of the differential pressure valve 3 is connected to the suction port 1 of the compressor 1 via the pressure outlet pipe 15 and the capillary tube 14.
When the compressor 1 is in operation, the pressure at the pressure introduction port 3a decreases due to the suction pressure of the compressor 1, and the differential pressure valve 3 becomes open.

A bellows 16 as a pressure responsive body is provided in the casing 7 of the valve device 9, and the bellows 16 divides the inside of the casing 7 into two chambers, a refrigerant circulation chamber 17 and a heat-sensitive medium enclosure chamber 18. Among these, the refrigerant distribution chamber 17 communicates with the refrigerant passage 8a and the communication passage 13, and the refrigerant circulates therein.On the other hand, the heat-sensitive medium interpersonal chamber 18 is formed as a closed space, and the heat-sensitive medium 19 is sealed inside. There is. In this embodiment, the heat-sensitive medium 19 is the same as the refrigerant flowing through the refrigerant passage 8a. The bellows 16 is configured to be able to expand and contract in the vertical direction in the drawing so as to approach or move away from the outlet 12, and a mounting seat 20 is provided on the upper end surface of the bellows 16.
The valve body 21 is taken up through the valve. Furthermore, bellows 16
A compression spring 2 is installed between the upper end surface and the upper end surface of the casing 7.
2, a heat-sensitive medium enclosure chamber 18 and a refrigerant distribution chamber 17.
When the internal pressure difference ΔP between The elastic force of the compression spring 22 is appropriately set so that the valve body 21 is in pressure contact with the outlet 12.

Next, the operation of the above configuration will be explained. When the compressor 1 is in operation, the suction pressure of the compressor 1 is applied to the differential pressure valve 3 through the capillary tube 14 and the pressure outlet pipe 15.
Since the pressure on the pressure introduction port 3a decreases, the differential pressure valve 3 becomes open. As a result, the high-temperature refrigerant discharged from the discharge port 1a of the compressor 1 passes through the refrigerant flow chamber 17 in the casing 7 and reaches the condenser 2, where it dissipates heat and liquefies, and then flows into the cooler 5 and stores it. The circulation is repeated in that the compressor is used for cooling inside the compressor, and finally returns to the suction port 1b of the compressor 1. When the compressor 1 is operated, the compressor 1
The temperature Tc of the refrigerant compressed within the chamber increases as shown by the dotted line in FIG. Such a high-temperature refrigerant flows through the refrigerant distribution chamber 17 of the device 9 configured from the discharge port 1a of the compressor 1.
As a result, the temperature To of the refrigerant in the refrigerant circulation chamber 17 also increases as shown by the solid line in FIG. The high-temperature refrigerant in the refrigerant circulation chamber 17 heats and expands the heat-sensitive medium 19 in the heat-sensitive medium enclosure chamber 18 through the bellows 16, and the internal pressure Pi of the heat-sensitive medium enclosure chamber 18 increases as shown by the solid line in FIG. It gets expensive. In contrast, the internal pressure P of the refrigerant circulation chamber 17.

maintains a relatively low value as shown by the dotted line in Figure 3, so the pressure difference ΔP between the two houses 17.18 (ΔP=Pi−Po
) to the closing operating pressure difference P o (
0.2 kg/cJ).

As a result, the bellows 16 expands in the direction (upward) of the outlet 12 against the elastic force of the compression spring 22 due to the expansion of the heat-sensitive medium 19, and as a result, the valve body 21 comes into pressure contact with the outlet 12, causing the outlet 12 to open. become closed. According to the experimental results of the present inventor, it has been confirmed that the valve body 21 closes several seconds after the compressor 1 is started.

When the inside of the refrigerator is cooled down to a set temperature or lower by the operation of the compressor 1, the compressor 1 is stopped at that point. Simultaneously with the stop of the compressor 1, the supply of high-temperature refrigerant into the refrigerant flow chamber 17 of the valve device 9 is also stopped, so that the refrigerant temperature To in the refrigerant flow chamber 17 drops rapidly as shown in FIG. As the refrigerant temperature TO in the refrigerant flow chamber 17 decreases, the temperature of the heat-sensitive medium 19 in the heat-sensitive medium enclosure chamber 18 decreases, and as a result, the heat-sensitive medium 19 contracts and the internal pressure P1 of the heat-sensitive medium enclosure chamber 18 decreases. As shown in FIG. 3, the pressure decreases rapidly immediately after the compressor 1 stops. As a result, the pressure difference ΔP between the compartments 17 and 18 decreases rapidly immediately after the compressor 1 stops, as shown in FIG.
/ Becomes a CD. Therefore, the bellows 16 contracts downward due to the elastic force of the compression spring 22, and the valve body 21 moves to the first position.
As shown in the figure, it moves away from the outlet 12, and the outlet 12 becomes open. According to the inventor's experimental results,
It has been confirmed that the valve body 21 opens 20 to 30 seconds after the compressor 1 stops. Immediately after the compressor 1 stops, the pressure on the discharge port 1a side is high and the pressure on the suction port lb side is low; however, after the compressor 1 stops,
In 0 seconds, the valve body 21 is opened and the outlet 12 of the casing 7 is opened.
is in an open state, so the high-pressure refrigerant on the discharge port la side of the compressor 1 flows from the outlet 12 of the casing 7 through the communication passage 13 to the suction port la side of the compressor 1. As a result, the pressure on the suction side of the compressor 1 rises rapidly, and along with this, the pressure inlet port 3 of the differential pressure valve 3
The pressure on the a side also rises rapidly and the differential pressure valve 3 closes. By closing the differential pressure valve 3, the high temperature refrigerant on the condenser 2 side is prevented from flowing into the cooler 5 when the compressor 1 is stopped. Also, at this time, the pressure on the discharge port 1a side of the compressor 1 and the pressure on the suction port lb side are the same as those in the communication passage 13.
Through this, equilibrium is achieved in a short period of time, and the load upon subsequent startup of the compressor 1 is reduced.

In the case of the above embodiment, the discharge of compressor 1! : The Ila side and the suction port 1b side are connected by a communication passage 13, and the valve device 9 that opens and closes this communication passage 13 is opened and operated when the compressor 1 is stopped, so that when the compressor 1 is stopped, the discharge of the compressor 1 is The pressures on the outlet 1a side and the suction port 1b side can be reliably balanced, and the load upon subsequent startup of the compressor 1 can be reduced. Moreover, unlike conventional solenoid valves, the valve device 9 is not operated by electric power to open and close, but the heat-sensitive medium 19 is based on changes in the temperature of the refrigerant in the casing 7 as the compressor 1 starts and stops.
Since the valve body 21 is opened and closed by the expansion and contraction of the valve body, the same amount of electric power is not required to open and close the valve body 21. This can reliably reduce the overall power consumption. Moreover, not only is the configuration of the valve device 9 itself relatively simple, but a control circuit for controlling the opening/closing operation of the valve device 9 is not required, so it is advantageous in terms of cost compared to conventional electromagnetic valves.

Furthermore, in this embodiment, in order to prevent the high la refrigerant on the condenser 2 side from flowing into the cooler 5 when the compressor 1 is stopped, a differential pressure valve 3 is provided between the condenser 2 and the capillary tube 4. Since this differential pressure valve 3 is configured to be connected to the communication passage 13 via the pressure derivation pipe 15,
When the compressor 1 is stopped, the opening operation of the valve body 21 can rapidly increase the pressure acting on the differential pressure valve 3 via the communication passage 13 and the pressure outlet pipe 15, thereby preventing the closing operation of the differential pressure valve 3. This can be done reliably and quickly, and the high temperature refrigerant can be prevented from flowing into the cooler 5 when the compressor 1 is stopped.

In both of the embodiments described above, the bellows 16 was used as the pressure-responsive body of the valve device 9, but a diaphragm, for example, may be used instead. Further, the heat-sensitive medium sealed in the heat-sensitive medium filling chamber 18 is not limited to a refrigerant, and may be any other medium.

[Effects of the Invention] As is clear from the above description, the present invention makes it possible to reliably equalize the pressure between the discharge port side and the suction port side of the compressor through the communication passage after the compressor is stopped, so that the pressure can be reliably balanced after the compressor is started. In addition to reducing the load during operation, the same amount of electric power is not required to drive the valve body that opens and closes the communication passage, and thus the overall electric power consumption can be reliably reduced.

Furthermore, there is no need for a control circuit for controlling the opening/closing operation of the valve body, resulting in an excellent effect of reducing manufacturing costs.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a refrigeration cycle diagram, Fig. 2 is a temperature change characteristic diagram of the refrigerant in the compressor and in the refrigerant distribution chamber, and Fig. 3 is the refrigerant distribution chamber and the heat-sensitive medium. FIG. 4 is a characteristic diagram of changes in pressure within the enclosure chamber. FIG. 4 is a characteristic diagram of changes in pressure difference between the refrigerant circulation chamber and the heat-sensitive medium enclosure chamber. In the drawing, 1 is a compressor, 2 is a condenser, 3 is a differential pressure valve, 4 is a capillary tube (throttle device), 5 is a cooler, 7 is a casing, 9 is a valve device, 12 is an outlet, 16 is a bellows (pressure responsive body) ), 17 is a refrigerant circulation chamber, 18 is a heat-sensitive medium enclosure chamber (closed space), 19 is a heat-sensitive medium, 21 is a valve body, and 22 is a compression spring. Horse 1 Act 2 Figure 4

Claims (1)

[Claims] 1. A condenser, a throttle device, and a cooler are connected between a discharge port and a suction port of a compressor, and the refrigerant is provided between the discharge port of the compressor and the condenser, and the refrigerant from the discharge port circulates inside. a casing formed in the casing for communicating between an outlet and the suction port side of the compressor, and a communication path provided to form a sealed space in which a heat-sensitive medium is sealed in the casing, the outlet being configured to open and close. a pressure-responsive body having a valve body, and when the compressor is in operation, the pressure-responsive body is displaced such that the valve body closes the outlet due to expansion of the heat-sensitive medium due to heat of the refrigerant flowing in the casing. and when the compressor is stopped, the pressure-responsive body is displaced so that the valve body opens the outlet due to contraction of the heat-sensitive medium as the temperature in the casing decreases.