JPS59147970A - Capillary tube for 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 Field of the Invention The present invention relates to a capillary tube for a pressure reducing device used in a refrigeration device such as a household refrigerator.

Conventional configuration and its problems In general, in this type of refrigeration equipment, the optimal amount of pressure reduction varies depending on the operating conditions, as shown in Figure 1.
In the same system at an outside temperature of 15°C, which is the condition specified in C9607 Annex 3 Power Consumption,
As a result of measuring the amount of power consumption in each state by changing the amount of pressure reduction of the capillary tube, the amount of pressure reduction when the amount of power consumption is the minimum is a, as shown by the dashed line A.

On the other hand, if similar measurements were made at an outside temperature of 30°C,
As shown by the solid line B, the optimum amount of pressure reduction is b, which is larger than a. Therefore, when using a single capillary tube, one that achieves a pressure reduction between a and b is generally used, but this results in an increase in power consumption at either low or high outside temperatures. becomes.

As an improvement on this point, there is a refrigeration system shown in Figure 2, which consists of a compressor, a condenser, and a condenser. Capillary reach tube 3. Evaporator 4゜suction pipe 5
It is constructed by connecting in a ring. A heater 6 is arranged in an upstream portion of the capillary tube 3 in a heat exchange manner, and a downstream portion thereof is arranged in a heat exchange manner with a suction pipe 5. The heater 6 is energized by a thermostat or the like when the outside air temperature reaches a predetermined temperature (for example, an outside air temperature of 20° C.) or higher, and is turned off when the outside air temperature is lower than the predetermined outside temperature.

In this operation, when the outside air temperature reaches a predetermined temperature of 20°C or higher, a flash gas is generated in the refrigerant flowing inside the capillary tube 3 by energizing the heater 6, and the amount of pressure reduction is reduced by increasing the flow path resistance due to the increase in volume. When the outside air temperature is 20° C. or less, the heater 6 is not energized, so the amount of pressure reduction in the capillary tube 3 is the original one. Therefore, the relationship between the outside air temperature and the appropriate amount of pressure reduction is characteristic C shown in the dashed line in FIG. Since the amount of pressure reduction when the heater 6 is energized is the optimum amount of pressure reduction for an outside temperature of 30° C., this refrigeration system has step-like characteristics as shown by the solid line. Therefore, the amount of pressure reduction approaches characteristic C, which is the characteristic of the optimum amount of pressure reduction, but since electricity is required as an input to the heater 6, there is a problem in that the effect is halved.

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to provide a refrigeration system that self-controls the amount of pressure reduction based on changes in outside temperature without requiring any electrical control.

Structure of the Invention To achieve this object, the present invention uses a shape memory alloy in a capillary tube, which is a pressure reducing device, to change the internal cross-sectional area of the capillary tube by changing the outside temperature without any electrical input. By changing the flow path resistance in the pipe, the amount of pressure reduction is controlled.

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

In FIG. 4, 1 is a compressor, 2 is a condenser, 7 and 8 are capillary tubes, 4 is an evaporator, and 5 is an id pipe, which are connected in order to form a ring.

The capillary tube 7 is arranged so that it is always exposed to the outside air, and the capillary tube 8 is placed in the same manner as before.
It is a thin tube made of aluminum, and is arranged to exchange heat with the pipe 5. The capillary tube 7 is formed of a shape memory alloy in a zigzag shape, and when the outside air temperature reaches a predetermined temperature or higher, the shape is memorized so that the linear shape becomes a zigzag shape. In the zigzag-shaped corner portion 7a, the cross-sectional area inside the tube is reduced by -1 as shown in FIG. Therefore, in this state, the flow path resistance is increased to increase the amount of pressure reduction.

Below a predetermined outside temperature, the capillary tube 7 becomes straight, and the internal cross section becomes circular everywhere as shown in Figure 7, resulting in the original pressure reduction amount of the capillary tube 7. Therefore, Figure 3 The step-like characteristics shown in can be obtained without requiring external energy such as electricity. In addition, the use of shape memory alloy in one of the capillary tubes 7.8 can be reduced, and by changing only the amount of variation such as reduced pressure, the accuracy of changes in reduced pressure can be improved.

Moreover, by arranging the capillary tube 8 to the suction vibro in a heat exchange manner, the refrigerant in the capillary tube 8 can be cooled by heat exchange with the suction vibro, and cooling efficiency can be improved.

Effects of the Invention As is clear from the above explanation, the present invention uses a shape memory alloy in the capillary tube to change the internal cross-sectional area of the capillary tube in response to changes in outside temperature, thereby changing the flow path resistance. By doing so, it is possible to approach the characteristics of the optimum amount of pressure reduction with respect to temperature. Furthermore, since control is performed without requiring external electrical input, power consumption can be reduced by approximately 10% by optimizing the amount of pressure reduction.
This will enable you to demonstrate your 0th function.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the amount of pressure reduction and power consumption of the refrigeration system, Figure 2 is a schematic diagram of the conventional improved system, Figure 3 is a diagram of changes in the amount of pressure reduction in the conventional improved refrigeration system, and Figure 4 1 is a schematic diagram of a refrigeration system according to an embodiment of the present invention. FIG. 5 is a front view of the main part showing the state of the capillary tube when it is deformed, and FIGS. 6 and 7 are cross-sectional views taken along the lines ■-Vl' and ■-■' in FIG. ...Capillary tube. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
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Claims (1)

[Claims] Made of shape memory alloy, it responds to external temperature changes.
A capillary tube in a refrigeration system that changes its internal cross-sectional area.