JPH02279964A - Refrigerator - Google Patents

Abstract

PURPOSE:To prevent the generation of strange sound induced by vapor-liquid separated refrigerant, use effectively the entire area of a vaporizer and increase a cooling capacity by defining an inner diameter of an outlet pipe which introduces refrigerant in a vapor and liquid mixed state from an expansion valve to a vaporizer in a compression type refrigerating cycle. CONSTITUTION:In a compression type refrigerating cycle, an inner diameter of an outlet pipe 5, which introduces refrigerant in a vapor and liquid mixed state from an expansion valve 2 to a vaporizer 6, is designed 1.0 to 1.3 times an inner diameter of an inlet pipe 1 which introduces liquefied refrigerant to the expansion valve 2. This construction increases the velocity of atomized refrigerant flowing in the outlet pipe 5, eliminates vapor and liquid separation time, and rather promotes atomization, thereby preventing the generation of coarse liquefied particles. Moreover, agitation induced by high flow velocity promotes homogenization, the refrigerant flows into the vaporizer 6 and is distributed equally before vapor and liquid separation takes place, which prevents the generation of strange sound. Furthermore, since the refrigerant is equally distributed, the temperature distribution in the vaporizer 6 is equalized, thereby improving the cooling efficiency.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a refrigeration and cooling system, and more specifically, to a refrigerant passage from an expansion valve to an evaporator in a compression type refrigeration cycle. .

[Conventional technology]

FIG. 1 illustrates an expansion valve, an evaporator, and their piping, which are part of a conventional compression type refrigeration cycle. 1 is an artificial pipe that receives liquid refrigerant that has been compressed by a compressor (not shown), radiated heat in a condenser, and condensed through a liquid receiver, etc.; 2 is an expansion valve that reduces the pressure of the liquid refrigerant;
It is connected to the artificial tube 1 by an O-ring joint 3. A thick outlet pipe 5 that guides the depressurized refrigerant toward the evaporator is connected to the expansion valve 2 by another O-ring joint 4, and its tip is connected to the artificial side header of the serpentine evaporator 6. Some are connected to 7.

In Fig. 1, 8 indicates a refrigerant passage of the evaporator 6, 9 indicates a fin, 10 indicates a part of the header on the outlet side, and 11 indicates a pipe for sending the gaseous refrigerant toward the compressor. There is.

When the refrigeration cycle is operated, the pressurized liquid refrigerant passes through the inlet pipe 1 and enters the expansion valve 2, and the amount corresponding to the vaporization state in the evaporator 6 is reduced in pressure and expanded adiabatically, forming a mist. , that is, it becomes a mixed fluid of gas and granular liquid and passes through the outlet pipe 5.
The refrigerant enters the header part 7 on the artificial side of the evaporator 6, is divided into small parts, and while passing through a large number of thin pipes in the refrigerant passage 8 of the evaporator 6, absorbs heat from the surface of the passage 8 and the fins 9, The refrigerant itself is vaporized and becomes a gaseous refrigerant, which merges at a 1° angle of the outlet header and is sent to the compressor again through the pipe 11.

In this way, liquid refrigerant flows into the artificial pipe 1 on the upstream side of the expansion valve 2, and refrigerant that has been depressurized and expanded into a mist flows into the outlet pipe 5 on the downstream side. is 8+
It was customary to make the outlet pipe 5 much thicker than the inlet pipe 1, such that if the difference was n+n, the diameter of the outlet pipe 5 would be 127 man.

[Problem to be solved by the invention]

In conventional refrigeration cycles, it is normal for the refrigerant to make an abnormal noise as it flows from the expansion valve to the evaporator. A part of the gas is separated into a gas phase and a liquid phase, and this is caused by the liquid phase intermittently entraining the gas phase.

In addition, in the conventional method, due to the heterogeneity of the atomized refrigerant,
The refrigerant is not evenly distributed among the many thin pipes of the evaporator, and the flow of refrigerant inside the evaporator becomes pulsating.
This not only causes abnormal noise and further impedes uniform distribution, but also causes the evaporator to have different temperatures in some parts, making it impossible to efficiently exert its cooling capacity. .

The present invention aims to prevent the gas-liquid separation of the atomized refrigerant flowing from the expansion valve to the evaporator, which is the cause of these problems in conventional refrigeration cycles, and to obtain an effective means for further atomizing and homogenizing the refrigerant. , the problem to be solved by the invention.

[Indispensable means to solve problems]

In the refrigeration/cooling device of the present invention, in a compression type refrigeration cycle, the inner diameter of the outlet pipe that leads refrigerant in a gas-liquid mixture state from the expansion valve to the evaporator is equal to the inner diameter of the inlet pipe that leads liquid refrigerant to the expansion valve. It is characterized by being 10 times to 1.3 times.

[For production]

The liquid refrigerant flowing into the expansion valve through the artificial pipe passes through the pores of the expansion valve, is depressurized, expands, becomes a mist, and flows into the evaporator through the outlet pipe. However, the atomized refrigerant flowing through the outlet pipe is easily separated into liquid and gas, and the separated gas and liquid flows through the outlet pipe of the expansion valve and flows into the evaporator, causing abnormal noise. Since the refrigerant flowing through the outlet pipe is separated into liquid and gas and expands in volume, it is common sense to increase the diameter of the outlet pipe, but in the present invention, on the contrary, the outlet pipe of the expansion valve is increased in diameter. Because it is thinner than before,
The flow rate of the atomized refrigerant flowing in the outlet pipe is increased, and there is no impediment to gas-liquid separation, rather atomization is promoted and coarse droplets are no longer generated. In addition, homogenization progresses due to the turbulent action of the high-speed flow, and because of the high-speed flow, the gas flows into the evaporator and is evenly distributed before gas-liquid separation occurs, so no abnormal noise is generated. Furthermore, since the refrigerant is evenly distributed, the temperature distribution within the evaporator is also made uniform, improving cooling efficiency.

〔Example〕

As an embodiment of the present invention in a refrigeration cycle of a vehicle air conditioner, the basic structure was the same as the conventional serpentine type shown in FIG. 1, and the inlet pipe 1 was 8 mm in diameter. As the exit pipe 5, we have replaced the thick one with a diameter of 12.7 mm that was previously used, and replaced it with a much thinner one.
One with a diameter of 0 mm was used.

As another example, a second example in which the present invention is applied to a Dron cup type evaporator whose structure itself is well known is shown.
As shown in the figure. In this example, 21 is a liquid refrigerant inlet pipe (8 mm diameter is used), 22 is an expansion valve, 23 and 24 are O-ring joints, and 25 is a depressurized refrigerant to a Dron cup type evaporator 26. 27 is a part of the inlet side header, 28 is the evaporator 26
29 is a fin, 30 is a header section on the outlet side, and 31 is a pipe for sending the gaseous refrigerant toward the compressor.

In either case, a significant improvement was observed in the temperature distribution of the evaporator 6 or 26. FIGS. 3 and 4 show the temperature distribution in the case of implementing the above-mentioned embodiment in the Dron cup type evaporator 26. These diagrams are for the evaporator 26
The horizontal axis represents the position of each point on the evaporator 26 when viewed from the front, and the vertical axis represents the air temperature from the evaporator.
FIG. 3 shows the temperature distribution measured in a low flow area where the flow rate of the refrigerant is small, and FIG. 4 shows the temperature distribution measured in the high flow area where the flow rate of the refrigerant is large.

The solid line shows the case where the outlet pipe 25 with a diameter of 12.7 mm is used as in the conventional case, and the broken line shows the case where the outlet pipe 25 with a diameter of 10 mm is used. In either case, the temperature of the device according to the present invention is significantly reduced on the left side of the diagram, that is, at a location far from the artificial side piping of the evaporator 26. This is because the refrigerant flowing into the evaporator 26 does not undergo gas-liquid separation in the embodiment of the present invention and is atomized, so the mist refrigerant reaches a long distance, even in places far from the population of the evaporator 26. This shows that it actively evaporates and removes heat well.

As a result, it was found that the average temperature of the evaporator of this example was lowered by 4° C. compared to the conventional one.

Although this is a simple calculation, it is a value that makes it possible to improve the cooling capacity by about 20% under the same conditions. In particular, the improvement is remarkable in the low flow rate range where the refrigerant flow rate is small. This means that in a low flow rate region, the flow velocity of the atomized refrigerant in the outlet pipe 25 of the expansion valve 22 is low, so that gas-liquid separation is generally likely to occur.
This can be interpreted as a result of the flow rate being increased due to the use of No. 5, and gas-liquid separation no longer occurring.

As for how thin the inner diameter of the outlet pipe should be, as a result of many experiments, we found that it is larger than the inner diameter of the inlet pipe, but smaller than 1.3 times the inner diameter of the inlet pipe. I found out that it is good.

〔Effect of the invention〕

By means of the present invention, the atomized refrigerant that has been depressurized and expanded in the expansion valve flows into the evaporator at high speed in the form of homogeneous fine particles without being separated into gas and liquid, and is evenly distributed. The generation of abnormal noise due to the refrigerant is prevented, and the entire area of the evaporator is effectively utilized, thereby increasing the cooling capacity.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the vicinity of the serpentine type evaporator and expansion valve, Figure 2 is a front view showing the vicinity of the drone force/tub type evaporator and expansion valve, and Figures 3 and 4 are the main parts. FIG. 3 is a temperature distribution diagram showing the effects of the invention. 1.21... Artificial tube, 2322... Expansion valve,
5.25... Outlet pipe, 6,26... Evaporator.

Claims (1)

[Claims] In a compression type refrigeration cycle, the inner diameter of the outlet pipe that guides refrigerant in a gas-liquid mixed state from the expansion valve to the evaporator is 1.0 to 1.3 times the inner diameter of the inlet pipe that leads liquid refrigerant to the expansion valve.
A refrigeration/cooling device characterized by double the size.