JPH0626738A - Air conditioning apparatus - Google Patents

Abstract

PURPOSE:To reduce the generation of refrigerant noise and vibration noise during the passage of the refrigerant by providing a refrigerant flow form control pipe having a suction pipe and a delivery pipe arranged on the high pressure side of an expansion valve and providing a in the middle of the control pipe with porous plate having a plurality of refrigerant flow holes. CONSTITUTION:A refrigerant flow form control pipe 13 is arranged as nearer the expansion valve 5 side as possible in a piping 8 for interconnecting an expansion valve 5 and a condenser 3. The mechanism of the refrigerant flow form control pipe 13 comprises a suction pipe 15 and a delivery pipe 19, expanded and contracted at a constant angle being below 10 deg. at which a flow does not peel, and a porous plate 18 located therebetween and having a plurality of refrigerant flow holes 17 having an area equal to the line sectional areas of a refrigerant piping 8 on the condenser 3 side and a refrigerant piping 20 on the expansion valve 5 side. By damping energy in a way that air bubbles flowing to the orifice of the expansion valve 5 are previously separated into fine pieces, the generation of refrigerant noise during the generation of a slug flow where the flow of a refrigerant is formed in the shape of a cannonball is reduced and the generation of noise on the low frequency side owing to collision with the expansion valve 5 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus capable of reducing noise by controlling a flow of a refrigerant for reducing a refrigerant noise generated from a refrigeration cycle of an air conditioner.

[0002]

2. Description of the Related Art Conventionally, a refrigerating cycle for an air conditioner is composed of an evaporator, a condenser and a decompression section (expansion valve or capillary tube), and each device is sequentially connected by piping to form a closed circuit. The refrigerant is enclosed in the operation. In recent years, with such a device, there has been an increasing demand for noise reduction in response to an increasing demand for improvement in comfort with respect to intermittent noise generated when the refrigerant flows (hereinafter referred to as refrigerant noise). There is.
Above all, because it is possible to control the flow rate of the refrigerant,
In recent years, there have been attempts to prevent some noises from the refrigerant noises generated from the expansion valve, which has been used more and more. For example, in Japanese Utility Model Laid-Open No. 3-38599, a sliding plate formed of a plurality of communication holes with springs that move by receiving pressure on the high pressure side is provided on the upstream side of the orifice of the expansion valve, and the sliding plate moves There is one in which a part of the communication hole is opened and closed. According to this method, during the cycle operation, the sliding plate moves to the step portion of the valve body due to the high pressure of the refrigerant, and the communication hole is throttled to prevent the generation of noise. There has been proposed a method of separating from the stepped portion of the valve body in accordance with the decrease of the refrigerant pressure to widen the communication area of the communication hole to reduce the resistance.

[0003]

The loudness of the refrigerant noise generated from the expansion valve is influenced by the flow state of the refrigerant flowing into the upstream high pressure chamber 21. In particular, it has been clarified from the experimental studies by the present inventors that the noise becomes the largest in the slag flow in which the bullet-shaped bubbles and the liquid alternately appear even in the two-phase flow state of the liquid and the vapor. In the conventional expansion valve, the orifice 23 formed by the tip of the conical valve body 25 and the cylindrical valve seat 22 sharply depressurizes the high-pressure liquid refrigerant to form a refrigeration cycle. Here, the two-phase fluid of the vapor liquid having a large density difference is alternately applied to the orifices 2 having a constant opening degree.
Large pressure pulsations occur when flowing into 3. On the other hand, at the opening 26, the refrigerant sharply contracts in the circumferential direction between the conical valve body 25 and the valve seat 22, and at that time, the refrigerant is decompressed and diffused to form a jet flow. The jet flow collides with the wall of the valve body 24 to generate a pressure pulse, and a vortex with a specific cycle is emitted, so that the refrigerant noise increases. Furthermore, since the flow direction of the jet flow is forcibly changed to the right angle direction, a vortex due to the refrigerant jet flow is generated immediately after the opening 26 due to the pressure loss, and the valve body 25 and the valve seat 22 are vibrated to increase the sound.

An object of the present invention is to provide a noise suppression device for an air conditioner corresponding to an expansion valve, which can reduce the generation of refrigerant noise and vibration noise generated when the refrigerant passes through.

[0005]

In order to solve the above-mentioned problems, the present invention is an air conditioner equipped with an expansion valve in which a refrigerant flow rate can be arbitrarily changed in a refrigeration cycle, and is 10 degrees upstream of the expansion valve 5 on the high pressure side. A refrigerant flow mode control pipe 13 having a suction pipe 15 and a discharge pipe 19 that expand and contract at a fixed angle within is provided, and the suction pipe 15 and the discharge pipe 1 are provided in the middle of the control pipe 13.
A plurality of refrigerant circulation holes 17 having the same cross-sectional area as the refrigerant pipe 8 on the condenser 3 side and the refrigerant pipe 20 on the expansion valve 5 side connected to the pipe 9.
The perforated plate 18 having

[0006]

In the air conditioner using the expansion valve, in order to reduce the refrigerant noise generated when the noisy refrigerant flow is a bullet-shaped slag flow during cycle operation, the bubbles flowing into the expansion valve 5 are preliminarily set. In other words, the perforated plate 18 having a plurality of refrigerant circulation holes 17 is used to make it fine. At this time, in order to prevent decompression or increase in resistance at this portion, the suction pipe 1 that expands and contracts at a constant angle within 10 degrees.
The perforated plate 18 is provided in the refrigerant flow mode control pipe 13 including the discharge pipe 5 and the discharge pipe 19.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a refrigerating cycle of an air conditioner will be described in detail below with reference to FIGS. 2 is a system configuration of a conventional refrigeration cycle, and FIG. 1 is a system diagram of a system to which the present invention is applied.
Here, the cycle (during cooling) will be briefly described with reference to FIG. A condenser 3 is connected to the discharge side of the compressor 1 in the figure, and the condenser 3 condenses the vapor refrigerant discharged from the compressor 1 with cooling air blown by a cooling fan 4 ( High pressure liquid refrigerant). Next, the condensed liquid refrigerant flows into the expansion valve 5 which is the object of the present invention, and the liquid refrigerant that has entered here is decompressed and expanded. The gas-liquid two-phase refrigerant decompressed and expanded by the expansion valve 5 exchanges heat with the room air blown by the blower fan 12 in the evaporator 6 connected to the downstream side thereof to evaporate the liquid refrigerant. After that, the refrigerant that has been vaporized in the evaporator 6 to become vapor flows into the compressor 1 and is compressed again. In this refrigeration cycle, it is basically desirable that only the high-pressure refrigerant in the liquid flow flows on the upstream side of the expansion valve 5 during operation,
Due to bending in the process of installing the pipes and increase in resistance due to long pipes, cannonball-shaped bubbles 29 in the liquid refrigerant as shown in FIG.
A slag flow in which the liquid 14 and the liquid 14 alternately flow may occur. It has been known from the experiments by the authors that the noise becomes particularly loud when the slag flow flows in the vertical pipe from the bottom to the top as shown by the arrow 29 toward the expansion valve 5 as shown in FIG. . Therefore, FIG. 1 shows the cycle configuration of the present embodiment, FIGS. 4, 5 and 6 show concrete explanation diagrams, and FIG. 7 shows its effect. In the present invention, as shown in FIG. 1, the control pipe 13 of the refrigerant flow mode is provided between the expansion valve 5 and the pipe 8 connecting the condenser 3 and as close to the expansion valve 5 side as possible. The mechanism of the control pipe 13 of this refrigerant flow mode is shown in FIG.
As shown in FIG. 3, the suction pipe 15 and the discharge pipe 19 that expand and contract at a constant angle within 10 degrees without separation of the flow, and the refrigerant pipe 8 on the condenser 3 side and the refrigerant pipe 20 on the expansion valve 5 side in the middle thereof It is composed of a perforated plate 18 having a plurality of refrigerant flow holes 17 having the same cross-sectional area as the pipeline. In FIG. 5, the valve seat 22 of the expansion valve 5 and the discharge pipe 19 of the refrigerant flow mode control pipe 13 are directly connected. In this case, the total area of the plurality of refrigerant circulation holes 17 is equal to the sectional area of the refrigerant pipe 8 and FIG. 6 is an example showing the sectional area of the perforated plate 18 having the plurality of refrigerant circulation holes 17. However, in all cases, the total area of the holes is equal to the sectional area of the pipelines of the refrigerant pipe 8 and the refrigerant pipe 20 on the expansion valve 5 side.

Next, the operation of the control pipe 13 of the refrigerant flow mode, which is composed of the perforated plate 18 having the plurality of refrigerant circulation holes 17 in this embodiment, will be described. The refrigerant noise generated when the refrigerant flow as shown in FIG. 3 is a bullet-shaped slag flow is
Since the large bubbles 30 directly collide with the valve seat 22 and the main body 24 of the expansion valve 5, the bubbles flowing into the expansion valve 5 are finely divided in advance to attenuate the energy, and then the expansion valve 5
Flow into the orifice 23 of Therefore, the present invention was born. However, if the flow resistance is increased by the control pipe 13 of the refrigerant flow mode or if the pressure is reduced here, the efficiency of the refrigeration cycle is reduced, and therefore, in order to prevent these. The pipe connecting the front and rear of the perforated plate 18 is composed of a suction pipe 15 and a discharge pipe 19 that expand and contract at a constant angle θ shown in FIG.
The total area of the refrigerant circulation holes 17 provided in 8 is equal to the sectional area of the refrigerant pipe 8 and the refrigerant pipe 20 on the expansion valve 5 side. FIG. 7 shows a measurement result comparing noise in the frequency domain in the case where only the conventional expansion valve 5 is used and in the present embodiment shown in FIG. However, the experimental conditions at this time are
The slag flow was intentionally generated. As is clear from this figure, by using this embodiment, it is reduced by 5 to 15 dB from 250 to 800 Hz on the low frequency side, which is a problem with the refrigerant noise, compared to the conventional expansion valve 5 alone. From this, it can be seen that the method of combining the refrigerant flow mode control pipe 13 and the expansion valve 5 of the present invention is highly effective in reducing the refrigerant noise.

[0009]

According to the present invention, in order to make it possible to reduce the refrigerant noise generated when the refrigerant flow is a bullet-shaped slag flow, the air bubbles flowing into the orifice of the expansion valve are previously finely divided to save energy. Since the sound is damped, it is possible to reduce the sound on the low frequency side generated by the collision with the expansion valve.

[Brief description of drawings]

FIG. 1 is a system diagram when this embodiment is used.

FIG. 2 is a system diagram of a conventional expansion valve only.

FIG. 3 is an explanatory view of the flow of a slag flow having the largest refrigerant noise.

FIG. 4 is a specific cross-sectional view of this embodiment.

FIG. 5 is a specific cross-sectional view of this embodiment.

6 is a cross-sectional view taken along the line AA of FIG.

FIG. 7 is an explanatory diagram showing the results of comparing the noise of the refrigerant sound in the conventional embodiment with only the expansion valve and in the present embodiment.

[Explanation of symbols]

5 ... Expansion valve, 13 ... Refrigerant flow mode control tube, 17 ... Refrigerant flow hole, 18 ... Perforated plate, 23 ... Orifice, 30 ... Bubbles.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomomi Umeda 502 Jinritsucho, Tsuchiura-shi, Ibaraki Prefecture Hiritsu Seisakusho Co., Ltd.

Claims (1)

[Claims] 1. An air conditioner provided with an expansion valve capable of arbitrarily changing a refrigerant flow rate in a refrigeration cycle, comprising a refrigerant flow mode control pipe having a suction pipe and a discharge pipe upstream of a high pressure side of the expansion valve, An air conditioner comprising a perforated plate having a plurality of refrigerant circulation holes in the middle of a control pipe.