JPH1019419A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of the sound of a refrigerant at any time, even during the heating operation or during the temporary stoppage of operation, by providing a straight tube with the length thereof enough of make the size of bubble almost uniform as generated in the refrigerant at an inlet port during the heating operation at an indoor electric motor operated expansion valve. SOLUTION: A refrigerant pipe 51 linked to an indoor heat exchanger 13a and a flow divider 19a is once put downward vertically, bent almost in a U- shape and then, put upward vertically. In other words, a refrigerant pipe 51a to a connection port of an indoor electric motor operated expansion valve 14a employs a straight pipe whose length L is so specified that the size of bubble generated in the refrigerant can be almost uniform. Thus, the refrigerant containing the bubble is straightened within the straight pipe to make the size of the bubble almost uniform and then, flows into the room electric expansion valve 14a thereby enabling restricting of the sound of the refrigerant generated from the indoor electric motor operated expansion valve 14a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multi-type air conditioner and a heat pump type air conditioner.

[0002]

2. Description of the Related Art Generally, an indoor heat exchanger, a compressor, and an outdoor heat exchanger, for example, are installed in one outdoor unit.
2. Description of the Related Art A multi-type or heat-pump type air conditioner in which a plurality of indoor units each having a built-in electric expansion valve are connected in parallel is known (Japanese Utility Model Publication No. 4-10535). In such an air conditioner, for example, during the heating operation, to stop the operation of any of the indoor units of the plurality of indoor units, and to completely close the electric expansion valve of the stopped indoor unit, Since the condensed liquid refrigerant accumulates in the indoor heat exchanger of the indoor unit, the air conditioner as a whole is in a gas-out state, and there is a possibility that the capacity of the air conditioner is reduced. Therefore, even when the operation is stopped, the electric expansion valve of the stopped indoor unit is opened (the opening is set smaller than the opening during the normal heating operation), and the indoor heat exchanger in the stopped indoor unit is disconnected. The accumulation of the liquid refrigerant is prevented.

[0003]

As described above, even when one of the indoor units is stopped in the heating operation, the electric expansion valve of the stopped indoor unit is slightly opened, so that the refrigerant slightly flows. There is a problem that refrigerant noise is generated from the expansion valve.

In particular, in this electric expansion valve, since the valve opening is controlled by an electric motor (pulse motor), it is difficult to accurately set the predetermined valve opening due to a rotation error of the motor or the like. In addition to the fact that the refrigerant in a gas-liquid mixed state flows through the expansion valve during the heating operation and during the stoppage, when the two facts overlap, the above-described refrigerant noise becomes extremely loud. There was a problem.

A so-called wall-mounted type in which an indoor unit in which such an indoor heat exchanger and an electrically operated expansion valve are housed is installed in an exposed state on a wall surface of a room near an indoor living space. There is a problem that the refrigerant sound is particularly worrisome as compared with the so-called ceiling cassette type in which the indoor unit is embedded in the indoor ceiling.

Accordingly, an object of the present invention is to provide an air conditioner in which refrigerant noise is less likely to be generated regardless of whether the heating operation is performed or the operation is temporarily stopped.

[0007]

According to the present invention, there is provided an air conditioner having an outdoor unit, an indoor heat exchanger, and a plurality of indoor units in which an indoor electric expansion valve is sequentially connected by a refrigerant pipe. A straight pipe having a sufficient length for adjusting the size of bubbles generated in the refrigerant substantially uniformly is provided at an inlet port of the indoor electric expansion valve during a heating operation. .

According to a second aspect of the present invention, there is provided an air conditioner having an outdoor unit, an indoor heat exchanger, and a plurality of indoor units in which an indoor electric expansion valve is sequentially connected by a refrigerant pipe. Has an inlet port during the heating operation, a needle valve capable of opening and closing the inlet port, and an outlet port orthogonal to the inlet port during the heating operation, and an inlet port during the heating operation in the indoor electric expansion valve. Is characterized in that a straight pipe having a sufficient length is provided for adjusting the size of bubbles generated in the refrigerant substantially uniformly.

The invention described in claim 3 is the first or second invention.
Wherein the indoor heat exchanger is provided with a flow divider, and the number of passes of the indoor heat exchanger divided by the flow divider is set to a large value. .

According to these inventions, for example, in a multi-type air conditioner, when the operation of any of the indoor heat exchangers is stopped during the heating operation, the refrigerant is not accumulated in the indoor heat exchanger. The motor-operated valve is slightly opened to control the refrigerant to flow little by little. In this case, since the refrigerant flowing little by little is in a gas-liquid mixed state, an unpleasant refrigerant noise is generated when the refrigerant flows into the electric expansion valve as it is. According to the present invention, the refrigerant in the gas-liquid mixed state flows into the electric expansion valve after passing through the straight pipe having a sufficient length for adjusting the size of bubbles generated in the refrigerant to substantially uniform. Therefore, generation of harsh refrigerant noise is suppressed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a multi-type air conditioner. This air conditioner 1 has a plurality of indoor units 3 for one outdoor unit 2.
a, 3b, 3c are connected in parallel by a refrigerant pipe.

In the outdoor unit 2, reference numeral 4 denotes a variable capacity compressor, and 5 denotes a rated (constant capacity type) compressor which is connected in parallel. Reference numeral 6 denotes a four-way valve, which is set to a solid line state during the cooling operation and to a broken line state during the heating operation. And
The refrigerant discharged from the compressors 4 and 5 flows in a solid arrow state during the cooling operation and flows in a broken arrow state during the heating operation. 7
Are arranged in parallel with an outdoor heat exchanger.

The outdoor heat exchanger 7 functions as a condenser during a cooling operation and as an evaporator during a heating operation. 8 is a receiver tank. Reference numeral 9 denotes an accumulator which is connected to the blowing pipes 10 of the two compressors 4 and 5.

On the other hand, the indoor unit 3a is of a general wall type, and as shown in FIG.
12a, an indoor heat exchanger 13a, a flow distributor 19a, and the like are incorporated. The indoor heat exchanger 13a functions as an evaporator during the cooling operation and as a condenser during the heating operation. 1
Reference numeral 4a denotes an indoor motor-operated expansion valve (hereinafter referred to as "motor-operated valve"). The valve opening of the motor-operated valve 14a is controlled by a pulse motor built in the motor-operated valve. Becomes

Reference numeral 18a denotes an auxiliary pressure reducer. According to this embodiment, as shown in FIG. 2, there is provided a flow path resistor 101 made of an orifice plate for reducing the flow path area. And
Downstream of the flow path resistance 101 at the time of the heating operation, in order to make the size of bubbles generated in the refrigerant flowing through the refrigerant pipe substantially uniform at the time of the heating operation, a triangular pyramid-shaped bag net shape is tapered toward the downstream. A rectifying member (“screen”) 103 is provided.

The equipment in the other indoor units 3b and 3c is the same as the equipment in the indoor unit 3a, and therefore, is assigned substantially the same reference numerals and description thereof is omitted.

In the multi-type air conditioner 1 having such a configuration, when all the indoor units 3a, 3b, and 3c are operated for heating, the respective indoor units 3a, 3
The motorized valves 14a, 14b, 14c of b, 3c are set to the degree of opening corresponding to the heating load of the indoor unit. On the other hand, in the outdoor unit 2, the operating states of the two compressors 4.5 are controlled based on the total heating load of each indoor unit.

Here, for example, when only one indoor unit 3a has a heating load of "0" (other indoor units 3a).
The heating loads of b and 3c are not “0”), and the heating operation of this one indoor unit 3a is stopped. Specifically, the operation of an indoor blower (not shown) is stopped, and
The pulse motor of 4a is set to 85 pulses.

Incidentally, during normal heating, it is set to 115 pulses. That is, when the heating operation is stopped, the electric valve 1
The valve opening of 4a is set smaller than the valve opening during the heating operation.

The reason why the motor-operated valve 14a is set to be slightly open even when the heating operation is stopped is that even if condensed refrigerant is accumulated in the indoor heat exchanger 13a, the accumulated refrigerant is slightly opened. This is for returning to the outdoor unit 2 via the electric motor valve 14a.

However, when the electric valve 14a of the indoor unit 3a during the stoppage of the heating operation is slightly opened and the refrigerant flows, referring to FIG. 1, the refrigerant flowing through the flow divider 19a, the bent portion of the pipe, etc. Bubbles are generated. If the size of the bubbles varies in size and the refrigerant containing the bubbles directly flows into, for example, the electric valve 14a, a loud refrigerant noise is generated through the electric valve 14a. This refrigerant sound is a so-called "jar" sound of refrigerant flowing, and is quite anxious in a quiet room.

To solve this problem, it is conceivable to attach a "putty" to the outer periphery of the motor-operated valve 14a, but the work of attaching the "putty" is troublesome.

According to this embodiment, even if bubbles are generated in the refrigerant flowing through the flow divider 19a, the bent portion of the pipe, and the like, the refrigerant containing the bubbles passes through the flow path resistance 101 formed of, for example, an orifice. After the pressure is reduced, the gas passes through a bag-shaped rectifying member 103 that tapers in a triangular pyramid shape toward the downstream, so that the size of the bubbles is adjusted to be substantially uniform through the rectifying member 103, so that the refrigerant generated from the motor-operated valve 14a The sound becomes a so-called “sharing” of the refrigerant flowing,
It is greatly silenced. According to this, the amount of “putty” attached to the outer periphery of the motor-operated valve 14a can be reduced.

Next, the indoor unit 3b during the heating operation will be described. Specifically, an indoor blower (not shown) is rotated, and the opening of the electric valve 14b is adjusted according to the heating load of the indoor unit 3b. Here, the adjustment is to slightly reduce the pressure-reducing resistance value with respect to the heating load. For example, if the valve opening should be set to about 23%, the valve opening is set to about 25% and reduced by about 2% (the valve opening is set to a large value).

When the pressure reducing resistance is slightly reduced in this way, the above-described auxiliary pressure reducer 18b is provided to compensate for the shortage (2%) of the resistance caused by the reduction. Therefore, the state of the refrigerant in the indoor unit 3b during the heating operation is as follows. First, the indoor heat exchanger 13
The refrigerant in the gas-liquid mixed state condensed by b is once depressurized by the auxiliary decompressor 18b, and then depressurized again by the electric valve 14b whose valve opening is set to be slightly larger. Here, since the valve opening is somewhat large, the generation of refrigerant noise can be suppressed to a small level. Then, the refrigerant that has been decompressed by the electric valve 14b and is in a liquid state is returned to the outdoor unit 2. Therefore, the indoor unit 3a during the heating operation is stopped even in the indoor unit 3b during the heating operation.
As in the case described above, the refrigerant noise is less likely to be generated.

Next, during the cooling operation, the state of the refrigerant passing through the indoor unit 3a (electrically operated valve 14a) is almost liquid. It is smaller than when heating through 14a. Therefore, at the time of cooling operation, the refrigerant noise does not cause a serious problem.

When the cooling operation is stopped, the indoor heat exchanger 13a is on the low pressure side of the refrigeration cycle, and the refrigerant in the indoor heat exchanger 13a is supplied to the outdoor unit 2 (compressor 4,
Since it is pulled to 5), the electric valve 14a is fully closed.

FIG. 3 shows another embodiment.

In the embodiment shown in FIG. 1, the orifice plate 1
Since the screen 01 and the screen 103 are separate bodies, it is difficult to reduce the size. In this embodiment, the orifice fitting 20
1 and the screen 203 are integrally formed. The screen 203 is a substantially conical wire mesh and has an entrance end 203.
a is welded to the metal fitting 201, and the metal fitting 201 is inserted into the inside of the refrigerant pipe and is locked to the step of the refrigerant pipe. In other words, the metal fitting 201 integrated with the screen 203 also functions as an orifice. According to this, since the metal fitting 201 and the screen 203 are integrated, the size can be reduced.

Further, another embodiment will be described.

In this embodiment as well, substantially in the same manner as in the above-described embodiment, for example, when the operation of any indoor heat exchanger is stopped during the heating operation in the multi-type air conditioner 1, this indoor heat exchanger The motor-operated valve is opened slightly so that the refrigerant flows little by little so that the refrigerant does not accumulate in the air.

When this control is applied, refrigerant noise is generated by the motor-operated valve as described above. In this embodiment, the refrigerant noise is suppressed by the following configuration.

Referring to FIG. 4, the refrigerant pipe 51 connected to the indoor heat exchanger 14a and the flow divider 19a is once lowered vertically downward and then bent substantially in a U-shape to be vertically bent. It is standing up. According to this embodiment, the rising length L of the refrigerant pipe 51 is set to be considerably longer than that of the conventional one.

However, it is not a condition to start up in the vertical direction. The refrigerant pipe 51 may be horizontal as long as the length L is linear.

In short, referring to FIG. 4, the electric valve 14a
The refrigerant pipe 51a up to the connection port may be a straight pipe having a predetermined length.

The length L of the refrigerant pipe 51 is a predetermined length capable of adjusting the size of the air bubbles generated in the refrigerant to a substantially uniform size. In this case, for example, it is set to about 150 mm.

According to the test using the actual machine, the refrigerant pipe 51
When a copper tube having an outer diameter of 9.52 mm is used, when a refrigerant is caused to flow at a conventional length L = 50 mm, the sound of the refrigerant called “jar” is changed to “L” at a length of 70 mm or more. The sound of the refrigerant becomes "shar", the sound quality becomes low, and the noise of the refrigerant is reduced.

Referring to FIG. 2, the motor-operated valve 14a has an inlet port 81 during the heating operation, a needle valve 83 capable of opening and closing the inlet port 81, and an outlet port orthogonal to the inlet port 81 during the heating operation. 85.

According to experiments, the motor-operated valve 1 having such a configuration has been described.
In 4a, providing the above-described straight tube 51a is extremely effective.

Further, according to this embodiment, the number of passes of the refrigerant tubes constituting the indoor heat exchanger 14a is set to six passes which is larger than usual. When the number of passes is set to be larger than usual (for example, “6 passes” in the case of “2 passes”), the generation of refrigerant noise that spreads throughout the indoor heat exchanger 14a is suppressed. Therefore, it is possible to considerably suppress the sound of the generated refrigerant noise.

By providing the flow path resistance 101 and the rectifying member 103 described with reference to FIGS. 2 and 3 in the refrigerant pipe 51, harsh refrigerant noise generated from the indoor unit is significantly suppressed.

[0042]

As described above, for example, in a multi-type air conditioner, when the operation of any indoor heat exchanger is stopped during the heating operation, the refrigerant is not accumulated in this indoor heat exchanger. Then, the motor-operated valve is slightly opened to control the refrigerant to flow little by little. When applying this control,
According to the present invention, even if bubbles are generated in the refrigerant flowing through the flow divider or the bent portion of the pipe, the refrigerant containing the bubbles is rectified in the straight pipe having a predetermined length, and the size of the bubbles is increased. Flows into the motor-operated valve after being substantially uniformly adjusted, so that the refrigerant noise generated from the motor-operated valve is suppressed.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner of the present invention.

FIG. 2 is a sectional view showing a rectifying member.

FIG. 3 is a cross-sectional view showing another embodiment.

FIG. 4 is an explanatory diagram showing another embodiment.

[Explanation of symbols]

 2 Outdoor unit 3a to 3c Indoor unit 4,5 Compressor 7 Outdoor heat exchanger 13a to 13c Indoor heat exchanger 14a to 14c Expansion valve 15a to 15c Bypass pipe 16a to 16c Capillary tube 18a to 18c Auxiliary pressure reducer 51a Straight pipe 101 Flow resistance 103 Rectifying member

Claims (3)

[Claims] An air conditioner having an outdoor unit, an indoor heat exchanger, and a plurality of indoor units in which an indoor electric expansion valve is sequentially connected by a refrigerant pipe, wherein an inlet port of the indoor electric expansion valve during a heating operation. An air conditioner, further comprising a straight pipe having a sufficient length for adjusting the size of bubbles generated in the refrigerant substantially uniformly. 2. An air conditioner having an outdoor unit, an indoor heat exchanger, and a plurality of indoor units in which an indoor electric expansion valve is sequentially connected by a refrigerant pipe, wherein the indoor electric expansion valve is an inlet port during a heating operation. A needle valve capable of opening and closing the inlet port, and an outlet port orthogonal to the inlet port during a heating operation. The inlet port of the indoor electric expansion valve during the heating operation is generated in the refrigerant. An air conditioner comprising a straight pipe having a sufficient length for adjusting the size of bubbles substantially uniformly. 3. The indoor heat exchanger is provided with a flow divider, and the number of passes of the indoor heat exchanger divided by the flow divider is set to be large.
Or the air conditioner according to 2.