JPS6251392B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a throttling device for a refrigeration system, and an object of the present invention is to provide a novel throttling device that is inexpensive and has a wide control range.

Capillary tubes have mainly been used as throttling devices in conventional refrigeration equipment. This capillary tube has a simple structure, has no moving parts, is extremely inexpensive, and is often used as a throttling device in refrigeration equipment. However, since the resistance value of the capillary tube is fixed, if the compressor and heat exchanger are fixed, it will show maximum efficiency under certain temperature conditions, but
It has the disadvantage that efficiency decreases when these conditions are exceeded, and in the current era where high operating efficiency is required under a wide range of temperature conditions, it has not been able to meet the demands.

The present invention provides a heating device, a heat-sensitive device heated by the heating device, a capillary tube that operates in conjunction with the heat-sensitive device, and a capillary tube that connects a condenser and an evaporator, and a refrigerant between the heat-sensitive device and the capillary tube. are connected so as to flow in series, and the heat-sensitive device is partially or entirely formed of an alloy having a shape memory effect, thereby solving the drawbacks of the conventional capillary tube. An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 shows the mounting position of the diaphragm device 1 of the present invention. 2 is a compressor, 3 is a condenser, and 4 is an evaporator. A conventional first capillary tube 5 and a second capillary tube 6 are installed before and after the expansion device 1.
are connected in series.

Next, the detailed structure of the present invention will be explained with reference to FIG. A heating device 7 is connected to a power source 8 and a control device 9 that controls the amount of electricity. 1
0 is heated by the heating device 7, and the heating device 7
This heat-sensitive device is partially or entirely formed into a hollow bellows tube shape from an alloy that has a shape memory effect that contracts in the axial direction when the amount of heating increases and expands in the axial direction when the amount of heating decreases. 14 is the thermal device 1
A first capillary tube 5 communicates with one end 13 of the axially open end of the heat sensitive device 10 and integrally interlocks with the heat sensitive device 10; The capillary tube 15 is a second capillary tube having an inner diameter larger than the outer diameter of the first capillary tube 14 . A second capillary tube 6 communicates one open end 16 of the second capillary tube 15 with the condenser 3.

The other open end 17 of the first capillary tube 14 opens coaxially into the second capillary tube 15 .
As the heat-sensitive device 10 moves in its axial direction (in the direction of the solid arrow), the capillary tube 14 slides in the second capillary tube 15 in the axial direction.

Next, the configuration of the heat-sensitive device 10 will be explained in more detail. The heat-sensitive device 10 is partially or entirely made of an alloy having a shape memory effect. Certain alloys can memorize a desired shape, and even if they are deformed into a different shape after such memorization, they will return to the memorized shape when heated above a certain temperature, and then When removed, it begins to deform again towards the different shape mentioned above. Such alloys are called "shape memory alloys" or "alloys with shape memory effect."

Referring to FIGS. 4a and 4b, the movement of a heat-sensitive device 16 made of a shape memory alloy and formed into a coil shape, for example, will be explained. In this case, the heat-sensitive device 16 stores a shape with length l=l ₁ . l this
When it is stretched to = l ₂ (point A) and then heated, once it exceeds a certain temperature (point B), it begins to shrink rapidly and returns to its originally memorized shape (l = l ₁ ) (C
point). When heating is stopped and the temperature is lowered, a certain temperature (D
point), the length l begins to increase again at a lower point. When l reaches a certain point (point E, l=l ₃ ), if it is heated again, it passes through point F (same temperature as point B) and returns to the memorized shape (point C). The length l of the heat-sensitive device 10 in FIG. 2 corresponds to point E (l=l ₃ ) in FIG. 4b.

Next, FIG. 3 shows a state in which the heat-sensitive device 10 assumes the memorized length l=l ₁ due to the shape memory effect described above. FIG. 3 shows a state in which the amount of current applied to the heating device 7 is increased by the control device 9, and the heat-sensitive device 10 is sufficiently heated. Figures 2 and 3
Comparing the figures, it can be seen that the length l of the heat-sensitive device 10 changes depending on the amount of current, that is, the amount of heating. In Fig. 2, the total throttle resistance value on the refrigeration cycle is its length L = (length l ₄ of capillary tube 5) + (length l 5 of capillary tube 6) + (length l ₅ of capillary tube 14) l ₆ ) + (length of second capillary 15
l ₇ ). When the heat-sensitive device 10 is heated to the state shown in FIG. 3, the total throttling resistance value on the refrigeration cycle increases. That is, compared to the state in FIG. 2, the length l ₃ of the heat-sensitive device 10 is reduced to l ₁ , so the capillary tube 14 moves to the left in FIG. 2, and as a result, the length of the second capillary tube 15 is This is because s l ₇ increases. As is clear from the above explanation, the control device 9
By controlling the amount of electricity supplied to the heating device 7, it is possible to control the total throttling resistance value on the refrigeration cycle. In this case, as an input signal to the control device 9, the evaporator 4
The degree of superheating of the refrigerant at the outlet of the refrigerant or the degree of subcooling of the refrigerant at the outlet of the condenser 3 is suitable.

As described above, in the aperture device of the present invention, the basic aperture mechanism itself is the same as that of the conventional capillary tube, and it is only necessary to interpose a heat-sensitive device that responds to the amount of heating in series with the capillary tube. , does not require any high-precision machining. Therefore, the conventional capillary tube had
Without sacrificing the advantages of being inexpensive and having a simple structure, it is now possible to directly convert the length L, which is proportional to the total aperture resistance, from the control signal, allowing for a wider range than conventional capillary tubes with a slight increase in cost. This provides excellent effects in that it is possible to change the refrigerant flow rate and prevent a decrease in the operating efficiency of the refrigeration cycle even if the temperature conditions change.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle diagram showing the arrangement of the expansion device in one embodiment of the present invention, Figs. 2 and 3 are cross-sectional views showing the operating state of the same embodiment, and Figs. 4 a and b are the shapes, respectively. FIG. 2 is a side view and an operation explanatory diagram of a heat-sensitive device made of a memory alloy. DESCRIPTION OF SYMBOLS 1... Throttle device, 2... Compressor, 3... Condenser, 4... Evaporator, 5... First capillary tube, 6... Second capillary tube, 7...
Heating device, 8...Power supply, 9...Control device, 10...
...Thermosensitive device, 14...First capillary, 15...
Second capillary.

Claims (1)

[Claims] 1. A heating device connected to a control device that controls the amount of current applied, and a shape that is heated by the heating device, contracts in the axial direction when the amount of heating by the heating device increases, and expands in the axial direction when the amount of heating decreases. a heat-sensitive device partially or entirely formed in the shape of a hollow bellows tube from an alloy having a memory effect; a first capillary tube that communicates with one of the axially open ends of the heat-sensitive device and integrally interlocks with the heat-sensitive device; a first capillary tube that communicates the other axial open end of the heat-sensitive device with the evaporator; a second capillary tube having an inner diameter larger than an outer diameter of the first capillary tube; and one of the second capillary tubes. a second capillary tube that communicates an open end of the first capillary with a condenser, the other open end of the first capillary being always coaxially disposed inside the second capillary. .