JPH07103594A - Multiroom type air-conditioner - Google Patents

Abstract

PURPOSE:To start the second and subsequent compressors in a state wherein a starting load thereof is small, eliminate fluctuation of an outlet temperature and thereby ensure comfortableness and the reliability of compressors at all times, regarding a method for starting the compressors in a plurality in a multiroom type air-conditioner. CONSTITUTION:A discharge pipe closing mechanism 36 is provided on the discharge pipe side of a plurality of compressors 25 and 26 of which the inside of a hermetically closed vessel is kept at a high pressure during an operation and which are made to communicate with each other by an oil equalizing pipe 32, and a suction pipe closing mechanism 27 on the suction pipe side thereof, while discharge pipes and suction pipes are connected together through a compressor-side two-way valve 33 and a compressor capillary 34, and thereby a state of pressure inside the hermetically closed vessel of a stopped compressor is balanced at a high pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioner, and more particularly to a method for starting a plurality of compressors.

[0002]

2. Description of the Related Art Conventionally, as a multi-room type air conditioner of this type, for example, there is one disclosed in Japanese Patent Laid-Open No. 64-70657.

The conventional multi-room air conditioner of the above-mentioned publication will be described below with reference to the drawings.

In FIG. 3, reference numeral 1 is an outdoor unit of a multi-room air conditioner, which includes a first compressor 2, a second compressor 3, a first oil separator 4, and a second oil separator 5.
It comprises a first check valve 6, a second check valve 7, a four-way valve 8, an outdoor heat exchanger 9, an outdoor expansion valve 10, a liquid tank 11, and an accumulator 12. An indoor unit 13 includes an indoor expansion valve 14 and an indoor heat exchanger 15.

The outdoor unit 1 and the indoor unit 13 are annularly connected by a liquid pipe 16 and a gas pipe 17 to form a refrigerant circuit. The first passage of the four-way valve 8 communicates with the discharge side of the first compressor 2 via the first check valve 6 and the first oil separator 4, and also the second check valve 7 and the second oil separator. 5 to communicate with the discharge side of the second compressor 3, the second passage of the four-way valve 8 is on the suction side of the first compressor 2 and the second compressor 3, and the third passage of the four-way valve 8 is It communicates with the gas pipe 17, one of the outdoor heat exchangers 9 communicates with the fourth passage of the four-way valve 8, and the other one of the outdoor heat exchangers 9 has a liquid pipe through the outdoor expansion valve 10. It is connected to 16.

The first oil separator 4 and the suction side pipe of the first compressor 2 communicate with each other through a first capillary 18, and the second oil separator 5 and the suction side of the second compressor 3 are connected. The pipe communicates with the second capillary 19. Further, the third capillary 20 and the electromagnetic two-way valve 2 are provided between the discharge side pipe and the suction side pipe of the second compressor 3.
A bypass pipe 22 is provided via 1. 23 is
It is an oil equalizing pipe that connects the bottoms of the first compressor 2 and the second compressor 3 to each other.

One of the indoor heat exchangers 15 has a gas pipe 17
The other side of the indoor heat exchanger 15 is connected to the indoor expansion valve 1
It is connected to the liquid pipe 16 via 4. It should be noted that three indoor units 13 are connected in this conventional example, and the subscripts a, b, and c are added to distinguish them.

Next, the operation of the multi-room air conditioner having the above structure will be described. First, the case of the cooling operation will be described. The flow of the refrigerant in this case is represented by a solid line arrow, and each indoor expansion valve 14a, 14b, 14c has an opening degree according to each indoor load.

The high-temperature high-pressure gas discharged from the first compressor 2 and the second compressor 3 is supplied to the first oil separator 4,
It is condensed and liquefied in the outdoor heat exchanger 9 through the second oil separator 5, the first check valve 6, the second check valve 7, and the four-way valve 8, and is passed through the outdoor expansion valve 10 to each chamber. Inner expansion valve 14
depressurized by a, 14b, 14c, and each indoor heat exchanger 15
After entering a, 15b and 15c and evaporating and vaporizing respectively,
It returns to the 1st compressor 2 and the 2nd compressor 3 via the four-way valve 8, and performs cooling operation.

Next, the case of heating operation will be described. The flow of the refrigerant in this case is indicated by a broken line arrow, and the indoor expansion valves 14a, 14b, 14c have openings corresponding to the indoor loads.

The high-temperature high-pressure gas discharged from the first compressor 2 and the second compressor 3 is supplied to the first oil separator 4,
Each indoor heat exchanger 15a, via the second oil separator 5, the first check valve 6, the second check valve 7, and the four-way valve 8,
The outdoor expansion valve 1 is guided to 15b and 15c, condensed and liquefied there, and passed through the indoor expansion valves 14a, 14b and 14c.
After being decompressed at 0 and entering the outdoor heat exchanger 9 to evaporate and vaporize, the first compressor 2 and the second compressor 3 are passed through the four-way valve 8.
Return to and perform heating operation.

Next, the activation of the second compressor 3 will be described. When the second compressor 3 is started, the operating frequency of the operating first compressor 2 is lowered, and at the same time, the electromagnetic two-way valve 21 is opened so that the high pressure side and the low pressure side of the second compressor 3 are closed. After the pressure is balanced and the starting load is reduced, the second compressor 3 is started, and then the operation frequency of the first compressor 2 and the second compressor 3 is set to the command frequency.

[0013]

However, in the above-mentioned configuration, when the second compressor is to be started, the operating frequency of the operating compressor is lowered to reduce the evaporation temperature during the cooling operation. Rises and the blowing temperature rises. Further, during heating operation, the condensing temperature decreases and the blowout temperature decreases. Therefore, the blowout temperature fluctuates every time the second compressor is started, and there is a problem that comfort is impaired.

The present invention has been made in view of the above problems.
It is an inexpensive specification, and the blowing temperature does not fluctuate.
It can be started with the starting load of the compressor after the unit is small,
It is intended to provide a multi-room air conditioner that can always ensure comfort and reliability of the compressor.

[0015]

In order to solve the above-mentioned problems, the present invention is directed to a plurality of compressors, an outdoor heat exchanger, and an outdoor side, in which a closed container is maintained at a high pressure during operation and communicated with each other by an oil equalizing pipe. An expansion valve, a discharge pipe closing mechanism provided in the discharge pipe of the compressor, a suction pipe closing mechanism provided in the suction pipe of the compressor, and an outdoor unit including a bypass mechanism connecting the discharge pipe and the suction pipe, An indoor unit consisting of an indoor expansion valve and an indoor heat exchanger is connected annularly with a gas pipe and a liquid pipe to balance the pressure state in the closed container of the stop compressor to a high pressure. Is.

In another aspect of the present invention, a plurality of compressors, an outdoor heat exchanger, an outdoor expansion valve, and a discharge pipe of the compressor, which are maintained at a high pressure in an airtight container and communicated with each other through an oil equalizing pipe, are provided. The discharge pipe closing mechanism provided in the, and the outdoor unit consisting of the oil leveling pipe closing mechanism provided in the oil leveling pipe, and the indoor unit consisting of the indoor expansion valve, the indoor heat exchanger, the gas pipe and the liquid pipe It is characterized in that the pressure state in the closed container of the stop compressor is balanced to a low pressure by connecting the two in an annular shape by means of a ring.

[0017]

In the multi-room air conditioner of the present invention having the above-described structure, when the second and subsequent compressors are started, the discharge side and the suction side of the starting compressors are closed to increase the pressure inside the closed container. By balancing, it is started in a state with a small load. Further, according to another aspect of the present invention, when starting the second and subsequent compressors, the discharge side of the compressor to be started and the oil equalizing pipe are closed to balance the inside of the hermetic container with a low pressure, so that the load is small. It is something to start.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a multi-room air conditioner of the present invention will be described below with reference to the drawings. The same parts as those of the prior art are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, reference numeral 24 is an outdoor unit of a multi-chamber air conditioner, and the discharge sides of the first compressor 25 and the second compressor 26 whose inside of the hermetically sealed container is maintained at high pressure during operation are The first of the first four-way valve 27a and the second four-way valve 27b respectively
It communicates with the road.

The first four-way valve 27a and the second four-way valve 27
The second path of b is the first compressor 25 and the second compressor 26.
Of the first outdoor heat exchanger 28a and the third passage communicates with one of the first outdoor heat exchanger 28a and the second outdoor heat exchanger 28b. And the other one of the second outdoor heat exchanger 28b is connected to the first outdoor expansion valve 2
9a and the second outdoor expansion valve 29b.

The fourth passage of the first four-way valve 27a is connected to the gas pipe 1
7 and the fourth passage of the second four-way valve 27b is connected to the gas pipe 17 via the gas-side two-way valve 30.
The four-way valve 27b and the gas-side two-way valve 30 are communicated with the suction side of the second compressor 26 via the gas-side capillary 31.

Reference numeral 32 is an oil equalizing pipe that connects the bottoms of the first compressor 25 and the second compressor 26, and makes the oil level in the closed container uniform.

The discharge side and suction side of the second compressor 26 are connected via a compressor side two-way valve 33 and a compressor capillary 34, and a check valve 35 is provided on the suction side. ing.

Next, the operation in such a configuration will be described. First, the case of the cooling operation will be described. The flow of the refrigerant in this case is represented by a solid line arrow, and each outdoor expansion valve 2
8a, 28b are fully opened, and the indoor expansion valves 14a, 14b,
14c is the opening degree according to each indoor load, the gas side two-way valve 30
Is open when two compressors are in operation, and is closed when one compressor is in operation, and the compressor-side two-way valve 33 is closed when two compressors are in operation and open when one compressor is in operation. .

The high-temperature high-pressure gas discharged from the first compressor 25 and the second compressor 26 is condensed and liquefied by the outdoor heat exchangers 28a and 28b via the four-way valves 27a and 27b, and the outdoor expansion valve The indoor expansion valve 14 is passed through 29a and 29b.
The indoor heat exchanger 15 is depressurized by a, 14b, and 14c.
After evaporating and vaporizing by a, 15b, and 15c, respectively, it returns to the 1st compressor 25 and the 2nd compressor 26 via the four-way valves 27a and 27b, and performs a cooling operation.

Next, the case of heating operation will be described. The flow of the refrigerant in this case is represented by a dashed arrow, the outdoor expansion valves 28a and 28b are opened according to the refrigerant circulation amount, the indoor expansion valves 14a, 14b and 14c are opened according to the indoor load, The gas side two-way valve 30 is open when operating two compressors, and is closed when operating one compressor, and the compressor side two-way valve 33 is
It is closed when operating two compressors, and open when operating one compressor.

The high-temperature high-pressure gas discharged from the first compressor 25 and the second compressor 26 is introduced into the indoor heat exchangers 15a, 15b, 15c via the four-way valves 27a, 27b.
After condensing and liquefying here, the indoor expansion valves 14a, 14b,
The pressure is reduced by the outdoor heat exchangers 29a, 29b via 14c, vaporized and vaporized by the outdoor heat exchangers 28a, 28b, and transferred to the first compressor 25 and the second compressor 26 via the four-way valves 27a, 27b. Return and perform heating operation.

Next, the activation of the second compressor 26 will be described based on the cooling operation. When only the first compressor 25 is operating, the second four-way valve 27b, which is the discharge pipe closing mechanism 36, is in the heating circuit state, the gas side two-way valve 30 is closed, and the suction pipe closing mechanism 37. The check valve 35 is closed, the second outdoor expansion valve 29b is fully closed, and the compressor-side two-way valve 33 is open. Therefore, the second compressor 2
The pressure inside 6 is maintained at a high pressure by the oil equalizing pipe 32.

When a start signal is input to the second compressor 26, the second compressor 26 is started from the above-mentioned state where the starting load is small, and the second four-way valve 27b is in the cooling circuit state and gas. The side two-way valve 30 is open, the discharge pipe closing mechanism 36 is open, the compressor side two-way valve 33 is closed, and the check valve 35, which is the suction pipe closing mechanism 37, is different from the check valve 35. It is opened by the pressure, and the cooling operation of the two compressors is performed.

At this time, looking at the operation of the first compressor 25, since it is not necessary to lower the operating frequency as in the conventional case, the evaporation temperature rises and the blown air temperature does not rise extremely. .

As described above, when the second compressor 26 needs to be started, the discharge pipe closing mechanism 36 and the suction pipe closing mechanism 3 are provided.
By closing 7 and bypassing the discharge side and the suction side of the second compressor 26, the inside of the second compressor 26 is balanced to a high pressure so that the compressor can be started with a small starting load. Thus, the operating frequency of the compressor can be prevented from being lowered, the fluctuation of the blown air temperature that has conventionally occurred can be eliminated, and the comfort can always be ensured and the reliability of the compressor can be ensured.

Next, a second embodiment of the multi-room air conditioner of the present invention will be described with reference to the drawings. The first
The same parts as those of the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 2, reference numeral 38 denotes an outdoor unit of a multi-room air conditioner, which connects the bottoms of the first compressor 25 and the second compressor 26 whose inside of the closed container is maintained at high pressure during operation. An equalizing pipe closing mechanism 40 is provided in the middle of the equalizing pipe 39.

Next, the operation in such a configuration will be described. First, the case of the cooling operation will be described. The flow of the refrigerant in this case is represented by a solid line arrow, and each outdoor expansion valve 2
8a, 28b are fully opened, and the indoor expansion valves 14a, 14b,
14c is an opening according to each indoor load, an oil leveling pipe closing mechanism 40
Is open when operating two compressors and closed when operating one compressor.

The high-temperature high-pressure gas discharged from the first compressor 25 and the second compressor 26 is condensed and liquefied by the outdoor heat exchangers 28a and 28b via the four-way valves 27a and 27b, and the outdoor expansion valve The indoor expansion valve 14 is passed through 29a and 29b.
The indoor heat exchanger 15 is depressurized by a, 14b, and 14c.
After evaporating and vaporizing by a, 15b, and 15c, respectively, it returns to the 1st compressor 25 and the 2nd compressor 26 via the four-way valves 27a and 27b, and performs a cooling operation.

Next, the case of heating operation will be described. The flow of the refrigerant in this case is represented by broken line arrows, the outdoor expansion valves 28a, 28b are opened according to the refrigerant circulation amount, the indoor expansion valves 14a, 14b, 14c are opened according to the indoor load, The oil leveling pipe closing mechanism 40 is opened when operating two compressors,
It is closed when operating one compressor.

The high-temperature high-pressure gas discharged from the first compressor 25 and the second compressor 26 is guided to the indoor heat exchangers 15a, 15b, 15c via the four-way valves 27a, 27b.
After condensing and liquefying here, the indoor expansion valves 14a, 14b,
The pressure is reduced by the outdoor heat exchangers 29a, 29b via 14c, vaporized and vaporized by the outdoor heat exchangers 28a, 28b, and transferred to the first compressor 25 and the second compressor 26 via the four-way valves 27a, 27b. Return and perform heating operation.

Next, the activation of the second compressor 26 will be described based on the cooling operation. When only the first compressor 25 is operating, the second four-way valve 27b, which is the discharge pipe closing mechanism 36, is in the heating circuit state, the gas-side two-way valve 30 is closed, and the second outdoor side is closed. Since the expansion valve 29b is fully closed and the oil leveling pipe closing mechanism 40 is closed, the second compressor 26
As for the internal pressure state, the low pressure state is maintained.

When a start signal is input to the second compressor 26, the second compressor 26 is started from the state where the starting load is small as described above, and the second four-way valve 27b is in the cooling circuit state and gas. The side two-way valve 30 is opened, the discharge pipe closing mechanism 36 is opened, the second outdoor expansion valve 29b is fully opened, the oil leveling pipe closing mechanism 40 is opened, and cooling operation of the two compressors is performed. .

At this time, looking at the operation of the first compressor 25, since it is not necessary to lower the operating frequency as in the conventional case, the evaporation temperature rises and the blown air temperature does not rise extremely. .

As described above, when the second compressor 26 needs to be started, the discharge pipe closing mechanism 36 and the oil leveling pipe closing mechanism 4 are provided.
By closing 0, the inside of the second compressor 26 is balanced to a low pressure so that it can be started in a state where the starting load of the compressor is small. By eliminating fluctuations in air temperature, comfort and reliability of the compressor can always be ensured.

In the embodiment, the case where the number of compressors is two has been described, but even when the number of compressors is three or more, similarly, if the pressures in the compressors to be started are balanced, they can be easily started without any problem. It goes without saying that it can be done.

[0043]

As is apparent from the above description, the present invention provides a plurality of compressors, an outdoor heat exchanger, an outdoor expansion valve, which are maintained at a high pressure in an airtight container and communicated with each other by an oil equalizing pipe. A discharge pipe closing mechanism provided in the discharge pipe of the compressor,
An outdoor unit including a suction pipe closing mechanism provided in the suction pipe of the compressor and a bypass mechanism connecting the discharge pipe and the suction pipe, and an indoor unit including an indoor expansion valve and an indoor heat exchanger, It is characterized in that it is connected in an annular shape by a pipe and a liquid pipe to balance the pressure state in the closed container of the stop compressor to a high pressure.

Therefore, when it is necessary to start the second compressor, the discharge pipe closing mechanism and the suction pipe closing mechanism are closed, and the discharge side and the suction side of the second compressor are bypassed. By balancing the inside of the compressor of No. 2 to a high pressure so that the compressor can be started in a state in which the starting load is small, it is possible to eliminate the decrease in the operating frequency of the compressor, eliminate the fluctuation of the blown air temperature that has occurred conventionally, It is possible to always ensure comfort and reliability of the compressor.

In another aspect of the present invention, a plurality of compressors, an outdoor heat exchanger, an outdoor expansion valve, and a discharge pipe of the compressor, which are maintained at a high pressure in an airtight container and communicated with each other through an oil equalizing pipe, are connected to each other. The discharge pipe closing mechanism provided in the, and the outdoor unit consisting of the oil leveling pipe closing mechanism provided in the oil leveling pipe, and the indoor unit consisting of the indoor expansion valve, the indoor heat exchanger, the gas pipe and the liquid pipe It is characterized in that the pressure state in the closed container of the stop compressor is balanced to a low pressure by connecting the two in an annular shape.

Therefore, when it is necessary to start the second compressor, the discharge pipe closing mechanism and the oil leveling pipe closing mechanism are closed to balance the inside of the second compressor to a low pressure, and the starting load of the compressor is reduced. It is possible to start up in a small state, the number of parts is small, and the specifications are inexpensive, so that it is possible to eliminate the conventionally occurring fluctuations in the temperature of blown air and always ensure comfort and reliability of the compressor.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a multi-room air conditioner according to a first embodiment of the present invention.

FIG. 2 is a refrigeration cycle diagram of a multi-room air conditioner according to a second embodiment of the present invention.

FIG. 3 is a refrigeration cycle diagram of a conventional multi-room air conditioner

[Explanation of symbols]

 13 Indoor unit 14 Indoor expansion valve 15 Indoor heat exchanger 24 Outdoor unit 25 First compressor 26 Second compressor 27 Four-way valve 28 Outdoor heat exchanger 29 Outdoor expansion valve 30 Gas two-way valve 32 Oil equalizing pipe 33 Compressor-side two-way valve 34 Compressor capillary 35 Check valve 36 Discharge pipe closing mechanism 37 Suction pipe closing mechanism 38 Outdoor unit 39 Oil equalizing pipe 40 Oil equalizing pipe closing mechanism

Claims (2)

[Claims] 1. A plurality of compressors, which are maintained at a high pressure in an airtight container during operation and communicated with each other through an oil equalizing pipe, an outdoor heat exchanger,
An outdoor unit including an outdoor expansion valve, a discharge pipe closing mechanism provided in a discharge pipe of the compressor, a suction pipe closing mechanism provided in a suction pipe of the compressor, and a bypass mechanism connecting the discharge pipe and the suction pipe. And an indoor unit consisting of an indoor expansion valve and an indoor heat exchanger are annularly connected by a gas pipe and a liquid pipe to balance the pressure state in the closed container of the stop compressor to a high pressure. A multi-room air conditioner. 2. A plurality of compressors, which are maintained at a high pressure in an airtight container during operation and communicated with each other through an oil equalizing pipe, an outdoor heat exchanger,
An outdoor unit including an outdoor expansion valve, a discharge pipe closing mechanism provided in a discharge pipe of the compressor, and an oil leveling pipe closing mechanism provided in the oil leveling pipe, an indoor side expansion valve, and an indoor side heat exchanger. A multi-room air conditioner characterized in that a pressure pipe and a liquid pipe are annularly connected to an indoor unit to balance the pressure inside the closed container of the stop compressor to a low pressure.