JPS63204070A - 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] (Industrial application field) This invention relates to a refrigeration system.

(Prior art) In a refrigeration system, the load on the system increases due to an increase in ambient temperature, etc., and the pressure of the refrigerant flowing in the high-pressure side piping increases, and this pressure increase increases the load on the compressor. There is a problem that the compressor may be damaged due to the increase in air pressure.

As a device to solve such problems, Japanese Patent Application Laid-open No. 60-9
One example is the device described in Japanese Patent No. 3262, and this device will be explained based on FIGS. 5 and 6.

In FIG. 5, 51 is a compressor, and this compressor 51
is connected to a condenser 53 by a first gas pipe 52. This condenser 53 is connected to an expansion mechanism 55 such as a capillary tube through a first liquid pipe 54.
is connected to an evaporator 57 by a second liquid pipe 56.

This evaporator 57 is connected to the compressor 51 by a second gas pipe 58. On the other hand, the first liquid pipe 54 and the second gas pipe 58 are connected by a bypass pipe 60, and the bypass pipe 60 only allows the flow of refrigerant from the first liquid pipe 54 to the second gas pipe 5. Normally closed on-off valve 61
is interposed.

This on-off valve 61 will be explained based on FIG. 6. 62 is a valve body, and this valve body 62 has an inlet 63 connected to the first liquid pipe 54 side and an inlet 63 connected to the second gas pipe 58 side. A flow path 65 is formed which communicates with the outlet 64 where the air is fed. A valve seat 66 is provided at a position closer to the inlet 63 of this flow path 65, and a spring retainer 66 is provided at a position closer to the outlet 64. A valve element 69 is disposed between the valve seat 66 and the spring receiver 68, and a bias spring 73 is interposed between the valve element 69 and the spring receiver 68. That is, the valve body 69
is urged toward the valve seat 66 by the spring force of the bias spring 73 and is in contact with the valve seat 66.

In the device configured as described above, during operation, the load on the device increases due to a rise in ambient temperature, etc., and the pressure of the refrigerant flowing through the first liquid pipe 54 increases, causing the first liquid pipe 54 and the second gas pipe to The force due to the refrigerant pressure difference between bias spring 73 and
When the spring force is overcome, the valve body 69 separates from the valve seat 66, and the refrigerant bypasses from the first liquid pipe 54 through the bypass pipe 60 to the second gas pipe 58.

When the refrigerant in the first liquid pipe 54 comes to be bypassed into the second gas pipe 58 through the bypass pipe 60, the refrigerant pressure in the first liquid pipe 54 decreases, and therefore the load on the compressor 51 decreases. This is intended to prevent the compressor 51 from being damaged due to a drop in the compressor 51.

(Problems to be Solved by the Invention) However, in the above device, since the opening/closing valve 61 has a structure in which the valve point is determined by the bias spring 73, there is a drawback that chattering is likely to occur. That is, when the on-off valve 61 opens as described above, the differential pressure across the valve seat 66 instantly decreases and the valve closes, while the first liquid pipe 54
If the refrigerant pressure at the target is still high, the valve will open again and the same opening and closing operation will be repeated, and this phenomenon will cause noise and refrigerant pulsation, reducing the stability of operation and the high pressure. This reduces the credibility of control.

This invention has been made to solve the above-mentioned conventional drawbacks, and its purpose is to prevent phenomena such as the above-mentioned chattering, thereby reducing noise and refrigerant pulsation, resulting in stable operation. An object of the present invention is to provide a refrigeration system capable of improving performance and reliability of high pressure control.

(Means for Solving the Problems) Therefore, in the refrigeration system of the present invention, piping 2.4. The high pressure section 4 and the low pressure section 8 of 6.8 are connected by a bypass pipe 1o, and the bypass pipe 1o has a normally closed on-off valve 11 that allows only the flow of refrigerant from the high pressure section 4 to the low pressure section 8. , 11a, in which the on-off valves 11, 11a are connected to a valve body 12, a high-pressure side port 13 of the valve body 12, and a low-pressure side outlet 1.
A valve seat 16 provided in a flow path 15 that communicates with the valve seat 16 and
The shape memory alloy spring 24.2 is composed of a valve body 9 that is biased toward the side and comes into contact with and separates from the valve seat 16, and a shape memory alloy spring 24.27 arranged in the flow path 15.
7 deforms in response to the high-temperature refrigerant passing through the flow path 15 to weaken the biasing force of the valve body 19 toward the valve seat 16 when the valve is opened, and also responds to a decrease in the temperature of the refrigerant during the valve opening. Then, the valve body 19 is configured to return to its original state so as to restore the biasing force toward the valve seat 16 side.

(Function) In the refrigeration system having the above configuration, the pressure of the refrigerant in the high pressure section 4 increases under the influence of an increase in ambient temperature during its operation, and the refrigerant pressure difference between the high pressure section 4 and the low pressure section 8 increases. becomes large and the force resulting from this pressure difference becomes larger than the biasing force of the valve body 19 in the valve closing direction, the on-off valves 11 and 11a open, and the refrigerant in the high pressure section 4 flows into the on-off valve 11.1laO. Channel 15
It will be bypassed to the bypass piping 10 through.

At this time, the shape memory alloy spring 24.27
deforms in response, and this spring force weakens the biasing force in the valve closing direction. When the refrigerant is bypassed in such a state and the refrigerant pressure in the high pressure section 4 decreases and its temperature decreases, the shape memory alloy springs 24 and 27 respond to the decrease in the temperature of the refrigerant and return to their original state. Therefore, the biasing force of the valve body 19 in the valve closing direction is restored, and the on-off valves 11 and 11a are closed by this biasing force. Since the shape memory alloy springs 24 and 27 are used to reduce the urging force that urges the valve body 19 in the valve closing direction in the state after the valve is opened, chattering is less likely to occur than in the past. It becomes difficult to do.

(Example) Next, a specific example of the refrigeration apparatus of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a refrigerant circuit diagram according to an embodiment of the refrigeration system of the present invention. In the figure, 1 is a compressor,
The discharge port of this compressor 1 is connected to a condenser 3 by a first gas pipe 2.
The condenser 3 is connected to an expansion mechanism 5 such as a capillary tube through a first liquid pipe 4. This expansion mechanism 5 is further connected to an evaporator 7 by a second liquid pipe 6, and this evaporator 7 is connected to the suction port of the compressor 1 by a second gas pipe 8. Note that an accumulator 9 is interposed in the second gas pipe 8. and the first liquid pipe 4
and the second gas pipe 8 are connected to each other by a bypass pipe 10, and an on-off valve 11 is interposed in the bypass pipe 10.

The details of this on-off valve 11 are shown in FIG.
A flow path 15 is formed that communicates the high pressure side port 13 connected to the side and the low pressure side outlet 14 connected to the second gas pipe 8 side, and the flow path 15 is located at a position near the high pressure side port 13. In this case, the valve seat member 17 forming the valve seat 16 is also connected to the high pressure side outlet 1.
Spring receivers 18 are provided at positions closer to 4.

A valve body 19 is arranged between the valve seat 16 and the spring receiver 18, and the base end of the valve body 19 has a spring receiver portion 20 facing the valve seat 16 side and a spring receiver portion 20 facing the spring receiver 18 side. A facing spring receiving portion 21 is formed respectively.

Note that the valve seat member 17 is formed with a spring receiving portion 22 that faces the spring receiving portion 20 . Between the spring receiver 18 and the spring receiver 21 of the valve body 19, there is a bias spring 23 that biases the valve body 19 toward the valve seat 16. A shape memory alloy spring 24 that expands when a predetermined temperature is reached is interposed between the valve body 19 and the spring receiving portion 20, and the biasing force of the bias spring 23 causes the tip of the valve body 19 to press against the valve seat. 16.

The temperature characteristics of the shape memory alloy spring 24 are shown in FIG. 4. As shown in the figure, the shape memory alloy spring 24 starts to undergo elongation deformation when the temperature reaches TI, and at a higher temperature T.
It has a characteristic of ending the elongation deformation when it reaches 2. Therefore, the shape memory alloy spring 24 used in this case has a temperature T2 at which the elongation deformation ends, which is higher than the refrigerant temperature T3 at which the refrigerant should be bypassed from the first liquid pipe 4 to the second gas pipe 8. Preferably, it is sufficiently low. However, it is also possible to adopt a shape memory alloy spring 24 that keeps the temperature of the high-pressure side refrigerant at an appropriate temperature between T1 and T2, and even in that case, it is possible to weaken the biasing force of the bias spring 23. be.

Next, the operating state of the refrigeration system having the above configuration will be explained.

During operation of this device, the pressure of the refrigerant in the first liquid pipe 4 increases due to the influence of an increase in ambient temperature, etc., and this is caused by the refrigerant pressure difference between the first liquid pipe 4 and the second gas pipe 8. When the force becomes larger than the urging force of the bias spring 23 of the valve body 19 in the valve closing direction, the on-off valve 11 will open. As a result, the refrigerant in the first liquid pipe 4 passes through the flow path 15 of the on-off valve 11 and is bypassed to the bypass pipe 10.

At this time, the shape memory alloy spring 24 deforms in response to the temperature of the high temperature refrigerant, and this spring force weakens the biasing force of the bias spring 23 in the valve closing direction. When the refrigerant is bypassed in this state and the refrigerant pressure in the first liquid pipe 4 decreases and its temperature decreases, the shape memory alloy spring 24 responds to the decrease in the temperature of the refrigerant and returns to its original state. Therefore, the biasing force of the bias spring 23 on the valve body 19 in the valve closing direction is restored, and this biasing force causes the on-off valve 11 to
is closed. In this state after the valve is opened, the valve body 1
The biasing force that biases the valve 9 in the valve closing direction is provided by the shape memory alloy spring 2.
4, chattering is less likely to occur than in the past. In addition, the above-mentioned on-off valve 1
When the valve 1 is closed, the force caused by the pressure difference is sufficiently smaller than the urging force of the bias spring 23 in the valve closing direction. In other words, even if the pressure of the refrigerant in the first liquid pipe 4 rises to some extent due to the influence of the ambient temperature and the pressure difference becomes large, the force caused by this pressure difference will not immediately become larger than the urging force. Therefore, the inconvenience of repeated opening and closing operations does not occur.

As explained above, in the above embodiment, the shape memory alloy spring 24, which expands when the temperature exceeds a predetermined temperature, is used in the opening/closing valve 1.
1, the shape memory alloy spring 24 expands immediately after the valve is opened, weakening the biasing force exerted by the bias spring 23, thereby preventing chattering, etc., thereby reducing noise and refrigerant pulsation. is reduced, and therefore it is possible to improve the stability of operation and the reliability of high pressure control.

Next, another embodiment of the refrigeration system of the present invention will be described with reference to FIG. As shown in the figure, this embodiment employs an on-off valve 11a having a configuration different from the on-off valve 11 in the above embodiment. That is, this on-off valve 11a
In this, a shape memory alloy spring 27 that contracts and deforms when the temperature exceeds a predetermined temperature is interposed between the spring receiver 18 and a spring receiver 26 formed at the base end of the valve body 19. A shape memory alloy spring 27 biases the valve body 19 in the valve closing direction. That is, in this embodiment, the force caused by the refrigerant pressure difference between the first liquid pipe 4 and the second gas pipe 8 overcomes the urging force by the shape memory alloy spring 27, and the on-off valve 11a opens, and the first liquid When the refrigerant in the pipe 4 flows into the flow path 15 of the on-off valve 11a, the shape memory alloy spring 27 contracts and deforms in response to the temperature of the refrigerant, thereby weakening the biasing force. When the refrigerant bypasses and the pressure of the refrigerant in the flow path 15 of the on-off valve 11a decreases, the shape memory alloy spring 27 responds to the temperature drop of the refrigerant and expands, thereby restoring the biasing force. As a result, the on-off valve 11a is closed. Therefore, it is possible to achieve the same effects as in the above embodiment in this embodiment as well, and therefore, the same parts are indicated by the same reference numerals and the explanation thereof will be omitted.

Although specific embodiments of the refrigeration system of the present invention have been described above, the refrigeration system of the present invention is not limited to the above embodiments (and may be implemented with various changes within the scope of the present invention). For example, in each of the above embodiments, the first liquid pipe 4 and the second gas pipe 8 are connected by the bypass pipe 10, but the bypass pipe 10 is connected to the first gas pipe serving as a high pressure section. 2 or the first liquid pipe 4 and the second liquid pipe 6 or the second gas pipe 8 serving as the low pressure section.

(Effects of the Invention) As described above, in the refrigeration system of the present invention, when the on-off valve is in the open state, the shape memory alloy spring is used to weaken the biasing force in the valve closing direction, thereby preventing chattering etc. Since this is prevented from occurring, noise and refrigerant pulsation are reduced, making it possible to improve operational stability and reliability of high pressure control.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant circuit diagram showing one embodiment of the refrigeration system of the present invention, Fig. 2 is a longitudinal sectional view of the on-off valve according to the above embodiment, and Fig. 3 is a diagram showing another embodiment of the refrigeration system of the invention. FIG. 4 is a graph schematically showing the temperature characteristics of a shape memory alloy spring, FIG. 5 is a refrigerant circuit diagram of a conventional device, and FIG. 6 is a vertical cross section of an on-off valve of a conventional device. It is a diagram. DESCRIPTION OF SYMBOLS 1... Compressor, 2... First gas pipe, 3... Condenser, 4... First liquid pipe (high pressure part), 5... Expansion mechanism, 6
...Second liquid pipe, 7...Evaporator, 8...Second gas pipe (low pressure section), 10...Bypass pipe, 11, 11a
...Opening/closing valve, 12...Valve body, 13...Inlet,
14...Outlet, 15...Flow path, 16...Valve seat, 1
9... Valve body, 24.27... Shape memory alloy spring.

Claims (1)

[Claims] 1. High-pressure parts of piping (2) (4) (6) (8) that connect the compressor (1), condenser (3), expansion mechanism (5), and evaporator (7) to each other to form a refrigerant circulation path. (4) and low pressure section (
8) is connected by a bypass piping (10), and the bypass piping (10) has a normally closed on-off valve (
11) A refrigeration system in which (11a) is interposed, wherein the on-off valve (11) (11a) has a valve body (12), a high pressure side inlet (13) and a low pressure side outlet (12) of the valve body (12). 14), and a valve body (19) that is biased toward the valve seat (16) and comes into contact with and separates from the valve seat (16). and shape memory alloy springs (24) and (27) arranged in the flow path (15), and the shape memory alloy springs (24 and 27) move the flow path (15) when the valve is opened. The above valve body (
19) to weaken the biasing force toward the valve seat (16) side, and the biasing force of the valve body (19) toward the valve seat (16) in response to the temperature drop of the refrigerant during valve opening. A refrigeration device characterized in that it is configured to return to its original state so as to restore it.