JPS60598Y2 - Separate air conditioner/heater - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a separate type air-conditioner/heater, and more particularly, to a separate type air-conditioner/heater in which a plurality of indoor units are connected to one outdoor unit via connecting pipes.

Conventionally, this type of air-conditioning/heating machine has branched out multiple source-side branch pipes and gas-side branch pipes from the liquid pipes and gas pipes piping to the outdoor unit, respectively, and connected connection pipes to these branch pipes to form these branch circuits. A plurality of indoor units are connected to the outdoor unit through the via, and an electromagnetic on-off valve is interposed in each of the branch pipes so that the on-off valve installed in the branch circuit of the indoor unit that is operated when the indoor unit is operated is opened. west,
Furthermore, pressure equalizing pipes are provided for each indoor unit, and these pressure equalizing pipes are connected to low pressure pipes that have low pressure during heating to prevent liquid from pooling inside the indoor unit due to refrigerant leaking from the on-off valve during heating. ing.

(Utility Model Application No. 50-45755).

However, according to the above configuration, if high-pressure refrigerant leaks from the on-off valve that is closed during heating and enters the indoor unit that is stopped, the oil in the refrigerant will separate due to this drop in pressure and cause an oil pool. This caused problems such as a lack of lubricating oil in the compressor, and because the high-pressure refrigerant was closed by the on-off valve, a shock sound was generated when the on-off valve was opened when the indoor unit was started operating after it was stopped. Furthermore, since expensive electromagnetic on-off valves are installed in the source side and gas side branch pipes, there is also the problem that the overall cost increases.

On the other hand, when this type of air conditioner is installed on site, the outdoor unit is installed at a predetermined location outdoors, and the multiple indoor units connected to this outdoor unit via the branch circuit are installed in each predetermined room. Because each indoor unit is installed in a
Furthermore, the indoor loads of each indoor unit are different.

As a result, uneven flow occurs when refrigerant is supplied to each indoor unit, especially during heating when the refrigerant is supplied and returned without going through the expansion mechanism in the branch circuit, resulting in differences in the amount of refrigerant circulating to each indoor unit, resulting in an inappropriate flow. There was a problem that a certain ability distribution could not be maintained.

However, in order to solve the above problems, we first eliminated the electromagnetic on-off valve provided on the gas side branch pipe and installed it only on the liquid side branch pipe, and this electromagnetic on-off valve was opened and closed by the start and stop of the indoor unit during both cooling and heating operations. In addition, a bypass circuit equipped with a pressure reducing mechanism is provided between the inlet side of these on-off valves during heating and the outlet side of the expansion mechanism to divert the refrigerant flowing to the indoor unit on the side that is stopped during heating. We proposed a separate type air-conditioner/heater in which the liquid is introduced into the pipe via a bypass circuit.

However, although this air conditioner can solve the above-mentioned problems of oil accumulation and shock noise, since the on-off valve is opened and closed by starting and stopping the indoor unit during both air conditioning and heating operation, power is consumed due to opening and closing. The bypass circuit requires a closing valve, and therefore not only cannot the problem of high cost be fundamentally solved, but also the problem of uneven flow cannot be solved at all.

Therefore, this invention fundamentally solves the problems of air conditioners and heaters that were proposed earlier, eliminates not only liquid accumulation in the indoor unit when heating is stopped, but also oil accumulation, and also eliminates the problem of shock noise. , it is possible to eliminate the need for a shut-off valve, and to save power by keeping the shut-off valve installed in the source side branch pipe closed (regardless of the operation mode) during heating. This eliminates the need for heating, making it possible to reliably provide heating according to the capacity of each indoor unit.

In order to achieve this objective, the present invention branches out a plurality of source-side branch pipes from the liquid pipe of the outdoor unit and a plurality of gas-side branch pipes from the gas pipe, and connects the liquid pipe with a heating expansion mechanism. In a separate type air-conditioning/heating machine, a plurality of indoor units equipped with a cooling expansion mechanism and an indoor coil are connected in parallel to a single outdoor unit equipped with a cooling expansion mechanism and an indoor coil via the source side branch pipe and the gas side branch pipe. Each source-side branch pipe is equipped with an on-off valve that opens and closes during cooling operation and remains closed during heating operation, while a bypass pipe that bypasses the on-off valve is installed in each of the intermediate closing valves. , each bypass pipe is provided with a capillary tube and a check valve that allows only the flow of refrigerant during heating, to prevent uneven flow in the branch circuit during heating, and to prevent the refrigerant flowing into the indoor unit on the stop side. This is characterized in that the liquid flows out to the liquid pipe side via a bypass pipe.

Embodiments of the present invention will be described in detail below based on the drawings.

In the drawing, two indoor units B and C are connected to one outdoor unit A, and the outdoor unit A has a suction pipe 21 and a discharge port connected to the suction port and discharge port of the compressor 1. A four-way switching valve 2 is connected via a pipe 22, and an outdoor coil 3, which becomes a condenser during cooling and an evaporator during heating, is connected to one switching port of the four-way switching valve 2 via a gas pipe 23. At the same time, a heating expansion mechanism 4 and a parallel circuit with a check valve 5 are interposed in the middle of the liquid pipe 24 connected to the outdoor coil 3, and two source side branch pipes 25 and 26 are branched from the tip thereof. ing.

Further, a gas pipe 27 is connected to one switching port of the four-way switching valve 2, and two gas side branch pipes 28 and 29 are branched from the tip of the gas pipe 27.

In addition, both of the indoor units B and C are equipped with an indoor coil 6 that serves as an evaporator during cooling and a condenser during heating.A refrigerant pipe 30 is connected to the coil 6, and an internal liquid pipe 30a of this pipe 30 is connected to the coil 6. A parallel circuit consisting of the cooling expansion mechanism 7 and the check valve 40 is interposed in the middle.

Connecting pipes 31 and 32 are connected to the source side branch pipes 25 and 26 and the gas side branch pipes 28 and 29 of the outdoor unit A to form a branch circuit, and these branch circuits are connected to the indoor unit A).
, C are connected to the liquid pipe 30a and gas pipe 30b, and the indoor units B and C are connected to the outdoor unit A.

However, in the air conditioner and heater shown in FIG. Bypass pipes 10 and 10 are provided, and a check valve 1 is provided in these bypass pipes 10 and 10 to allow only the flow of refrigerant during heating.
2.12 and capillary tubes 11, 11 are interposed.

In the configuration shown in the first example, when the on-off valves 8゜9 are closed on both the operation side and stop side during heating, and the operation switch is turned on only during cooling to operate indoor units B and C. , these indoor units B and C are opened and closed by turning on and off the thermostats installed in them.

Further, an outdoor fan 13 is attached to the outdoor coil 3, and an indoor fan 14 is attached to the indoor coil 6, respectively, and the indoor fan 14 is operated by turning on the operation switch during both cooling and heating. When stopping the indoor unit with a switch, the indoor unit on the stopping side)B
, C's indoor fans 14 are turned off as if they were to stop.

During cooling, the on-off valves 8 and 9 are operated by the thermostat.
When opening and closing the thermostat, the drive may be stopped or controlled at a very low speed by turning on and off the thermostat, or it may be driven at a constant speed by turning on the operation switch regardless of whether the thermostat is turned on or off.

In addition, even if the thermostat operates during heating, the on-off valve 8.9 is not energized and remains closed (if it is a normally closed type), but the indoor fan 14 is stopped or operated at a very low speed, as in the case of cooling. do.

However, in order to eliminate wasteful heat radiation and to further reduce liquid accumulation, the fan 14 can be turned on and off by turning on and off the thermostat.
All you have to do is stop driving.

In addition, the capillary tube 12 absorbs drifting current caused by disturbances such as the distance between the branch circuits, the height of the indoor units B and C relative to the outdoor unit A, or the difference in condensing capacity of the indoor coil 6 due to the heating load during heating. Provide as much resistance as possible, approximately 5 kg/c
Make it about J.

If this resistance is made too small, not only will it not be possible to absorb the drifting flow, but also the amount of refrigerant flowing to the indoor unit B or C that is stopped due to the operation of the operation switch or the operation of the thermostat will increase, resulting in a large heat loss, which is not preferable. If the temperature is too high, the amount of liquid refrigerant that accumulates will increase, which is undesirable.The value should be set to an appropriate value that satisfies these two conditions.

However, when performing cooling operation for only one room in the above configuration, the operation switch for the indoor unit (B or C) that requires cooling is turned on. The fan 13 and the indoor fan 14 of the driving indoor unit B or C are driven, and the on-off valve 8 or 9 of the source branch pipe 25 or 26 connected to the driving indoor unit B or C is opened, and the compressor 1 The refrigerant gas discharged from the four-way switching valve 2 enters the outdoor unit 3 as shown by the solid line arrow, condenses, and reaches the liquid pipe 30a of the indoor unit B or C from the source side branch pipe 25 or 26,
The air enters the indoor coil 6 via the cooling expansion mechanism 7, cools and evaporates the indoor air, and returns to the compressor 1 from the gas pipe 30b via the gas side branch pipe 28 or 29 and the gas pipe 27, forming a cycle.

At this time, the on-off valve 9 or 8 of the source branch pipe 26 or 25 connected to the stopped indoor unit C or B is closed, and the liquid refrigerant flowing through the liquid pipe 24 is
5, and even if it leaks from the on-off valve 8 or 9, the gas pipes 30b of indoor units B and C are connected to the low pressure side, so the leaked liquid refrigerant will flow to the stopped indoor unit B. Or it will not accumulate in C.

Further, when cooling two rooms at the same time, both the on-off valves 8 and 9 open, which is the same as in the case of cooling one room described above.

In this case, the on-off valves 8 and 9 are opened and closed by turning on and off the thermostat, so if the thermostat of one indoor unit B or C is activated and one on-off valve 8 or 9 is closed, the on-off valves 8 and 9 are closed in the same way as when cooling one room. Refrigerant does not flow from the source side branch pipe 25a or 26b.

Next, when performing heating operation for only one room, the operation switch of indoor unit B or C that requires heating is turned on as described above. At the same time, the compressor 1, the outdoor fan 13, and the indoor fan 14 of the driving-side indoor unit B or C are driven as in the case of cooling.

During heating, the opening/closing valves 8 and 9 remain closed and are not energized, regardless of whether the operation switch is turned on or not.

The refrigerant gas discharged from the compressor 1 passes through the four-way selector valve 2 and the gas pipe 27, as shown by the dotted line arrow in Figure 1, and is diverted to the gas side branch pipes 28 and 29, and is then diverted to the driving side indoor unit B or C.
and flows to the stop-side indoor unit C or B.

The refrigerant that has entered the indoor unit B or C on the operating side is completely condensed in the indoor coil 6 by the drive of the indoor fan 14, enters the bypass pipe 10 from the source side branch pipe 25 or 26, is depressurized through the capillary tube 11, and is reduced in pressure to the liquid pipe. 24, and is appropriately depressurized by the heating expansion mechanism 4 and then connected to the outdoor coil 3.
It goes into.

On the other hand, since the indoor fan 14 is stopped, the refrigerant that has entered the stopped indoor unit C or B does not completely condense in the indoor coil 6 and flows into the liquid pipe 30a in a liquid-gas mixed state.
It enters the bypass pipe 10 from the source side branch pipe 26 or 25, but the flow rate is very small because it contains gaseous refrigerant.

This refrigerant is then reduced in pressure to an intermediate pressure between the high pressure and the low pressure in the capillary tube 11, reaches the liquid pipe 24, and joins with the liquid refrigerant flowing from the operation-side indoor unit) B or C.

The refrigerant that flows from the locking indoor unit C or B into the liquid pipe 24 will contain gas refrigerant, and the amount of refrigerant that flows into the liquid pipe 24 can be adjusted by appropriately setting the capillary tube 11 to control the operation of the refrigerator. be limited to an extent that does not interfere with

However, as described above, indoor unit C or B on the side that stops during heating
Since the refrigerant and lubricating oil that have entered are returned to the compressor 1 via the bypass pipe 10 as described above, no liquid or oil pools will occur in this indoor unit C or B.

In addition, when heating two rooms at the same time, use the indoor units B and C.
Both indoor fans 14 are driven, and the liquid refrigerant completely condensed in the indoor coil 6 is passed through the bypass pipe 1.
0, is depressurized by the capillary tube 11, flows into the liquid pipe 24, is appropriately depressurized by the heating expansion mechanism 4, and returns to the compressor 1 via the outdoor coil 3. During this simultaneous heating, the liquid The refrigerant passes through each of the capillary tubes 11, and each tube 11 provides a predetermined resistance.

Therefore, the branch circuit may have lengths or shorts, or the indoor unit B
, even if there is a difference in the piping resistance of the branch circuit due to a difference in the height of ,
By providing the resistance, the resistance difference or pressure difference can be absorbed and drift can be prevented, and indoor units B and C
This allows the appropriate amount of refrigerant to be supplied for each type of refrigerant.

Next, when heating these two rooms at the same time, if the indoor thermostat of the indoor unit B or C in the - room is activated, the indoor fan 14 of the indoor unit in the - room will stop or operate at a slow speed, and the indoor fan 14 of the indoor unit in the - room will stop or operate at a slow speed. The refrigerant flow is the same as in the case where the refrigerant flows, and liquid accumulation in the stopped indoor unit B or C is prevented.

In the embodiments described above, a capillary tube was used as the pressure reducing mechanism, but other resistors may be used.

As described above, according to the present invention, each of the source side branch pipes is provided with an on-off valve that opens and closes during cooling operation and remains closed during heating operation, and each of the on-off valves Bypass pipes are provided to bypass the refrigerant, and each bypass pipe is equipped with a capillary tube and a check valve that only allows the flow of refrigerant during heating.
During heating, high-pressure gas refrigerant flows through the indoor unit even when it is stopped, so the indoor unit on the stopped side can be maintained at a high pressure, and therefore oil does not separate from the refrigerant. No shock noise is generated when the stopped indoor unit that has been stopped due to the operation of the operation switch or the operation of the indoor thermostat starts operating, and furthermore, costs can be reduced.

In addition, the refrigerant flowing into the indoor unit on the stop side during heating is depressurized via a bypass pipe equipped with a capillary tube and flows out to the liquid pipe side, so the on-off valve provided on the source side branch pipe is used during heating. , both the operation side and the stop side can be held in the closed state. Therefore, by using a energized open type solenoid valve for this on-off valve, it is possible to eliminate excess power consumption due to opening and closing operations, and save power, as well as to reduce the amount of electricity flowing into the indoor unit on the stop side. This prevents the refrigerant and oil from accumulating in the indoor unit.

Moreover, since the capillary tube has a resistance capable of absorbing the drift of the branch circuit that connects the indoor unit and the outdoor unit, when the indoor units are operated at the same time during heating, there is no difference in height between the installation positions of these indoor units. Even if there are differences in the piping resistance of the branch circuits, such as differences in the distance from the outdoor unit, lengths of the branch circuits, or differences in the number and angle of bending, or the indoor Even if there are differences in pressure drop due to different condensing capacities of the units, these differences can be absorbed and uneven flow of refrigerant can be reliably eliminated.

As described above, while a pressure equalizing circuit can be formed using the bypass pipe, it is also possible to prevent drifting during simultaneous operation without impairing this pressure equalizing function, and with a simple configuration, all of the above-mentioned conventional problems can be solved. This can be easily resolved.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant piping system diagram showing an embodiment of the present invention. A...Outdoor unit, B, C...Indoor unit, 4...Heating expansion mechanism, 6...
... Indoor coil, 7... Cooling expansion mechanism, 8,
9...Open/close valve, 10 bypass, 11...
・Capillary tube, 12... Check valve, 2
4...Liquid pipe, 27...Gas pipe, 25.
26... Source side branch pipe, 28, 29... Curved gas side branch pipe, 31, 32... Connection piping.

Claims (1)

[Scope of utility model registration request] A plurality of source side branch pipes 25 are connected to the liquid pipe 24 of the outdoor unit A,
26 from the gas pipe 27 to a plurality of gas side branch pipes 28, 29.
The cooling expansion mechanism 7 is connected to one outdoor unit A in which the heating expansion mechanism 4 is interposed in the liquid pipe 24 via the source side branch pipes 25, 26 and the gas side branch pipes 28, 29. In a separate type air-conditioning/heating machine in which a plurality of indoor units B and C each having an indoor coil 6 and an indoor coil 6 are connected in parallel, each of the source side branch pipes 25 and 26 is provided with a pipe that opens and closes during cooling operation and closes during heating operation. On the other hand, each of the on-off valves 8 and 9 is provided with a bypass pipe 10 that bypasses the on-off valve 8 and 9, and each bypass pipe 10 A separate type air-conditioning/heating machine characterized in that a capillary tube 11 and a check valve 12 that only allows the flow of refrigerant during heating are interposed in the air conditioner.