JPH0989397A - Cooling and heating combination apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a cooling and heating combination apparatus having a high reliability by assuring the lubricant of a compressor by reducing the discharging amount of the lubricant from an outdoor unit due to the overflow of the lubricant from an oil separator when a variable speed compressor or a constant-speed compressor is started. SOLUTION: A communicating tube 20 for communicating the upstream side of a variable speed side oil returning circuit 5 with the upstream side of a constant-speed side oil returning circuit 6 via a check valve 21 at the lower part than an overflowing position is provided. When a variable speed compressor 1 is already started and a constant-speed compressor 2 is started, the overflow of the lubricant is reduced by the movement of the lubricant containing a large quantity of refrigerant and stored in the separator 4 to the separator 3 via the tube 20, the discharge of the lubricant from an outdoor unit is reduced to assure the lubricant amounts of the compressors 1, 2, thereby enhancing the reliability. A solenoid valve or a flow regulating valve is used instead of the valve 21, and this apparatus also comprises means for moving the lubricant in the bidirectional directions between the separators 3 and 4 by reducing the opening time or flow rate of the solenoid valve or flow regulating valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to prevention of lubricating oil outflow in a cooling and heating apparatus in which a variable speed compressor and a constant speed compressor are installed in parallel in a single-system refrigerant circuit.

[0002]

2. Description of the Related Art A conventional air conditioner will be described below with reference to the drawings, taking Japanese Patent Laid-Open No. 2-272262 as an example.
FIG. 5 is a refrigerant cycle diagram showing a configuration of a conventional cooling and heating device. In the figure, 1 is a variable speed compressor, 2 is a constant speed compressor, 3 is a variable speed oil separator, 4 is a constant speed oil separator, 5
Is a variable speed side oil return circuit that returns the lubricating oil stored in the variable speed side oil separator 3 to the suction pipe while adjusting the flow rate, and 6 is the lubricating oil stored in the constant speed side oil separator 4. A constant speed side oil return circuit that returns oil to the suction pipe while adjusting the flow rate, 7 is a check valve that prevents discharge gas from entering the constant speed side oil separator 4 when only the variable speed compressor 1 is operating, and 8 is A connecting pipe that communicates between the check valve 7 and the oil separator 3 on the variable speed side with a four-way valve 9, 9 is a four-way valve, 10 is an outdoor heat exchanger, 11 is an outdoor expansion valve, 1
Reference numeral 2 is an outdoor fan, and 13 is an oil equalizing pipe that connects the outer shell of the variable speed compressor 1 and the outer shell of the constant speed compressor 2 to make the oil level uniform, and these form an outdoor unit 14. . Also, 15
Is an indoor heat exchanger, 16 is an indoor expansion valve, 17 is an indoor fan, and these form an indoor unit 18. Further, the outdoor unit 14 and the indoor unit 18 are connected in an annular shape to form a cooling and heating device.

The operation of the above configuration will be described. During cooling and heating, the refrigerant compressed by both the variable speed compressor 1 and the constant speed compressor 2 or by the variable speed compressor 1 alone becomes high-temperature high-pressure gas. Variable speed compressor 1 and constant speed compressor 2
, The refrigerant compressed by the variable speed compressor 1 passes through the variable speed side oil separator 3, and the refrigerant compressed by the constant speed compressor 2 passes through the constant speed side oil separator 4. Pass through. Further, when compressed only by the variable speed compressor 1, the refrigerant passes only the variable speed side oil separator 3 without reaching the constant speed side oil separator 4 by the check valve 7. As described above, the refrigerant that has passed through both or one of the variable speed side oil separator 3 and the constant speed side oil separator 4 passes through the outdoor heat exchanger 10 via the four-way valve 9, and is then transferred to the outdoor fan 12 by the outdoor fan 12. It exchanges heat with air to be condensed, becomes a high-pressure liquid refrigerant, passes through the outdoor expansion valve 11, is decompressed by the indoor expansion valve 16, becomes a low-temperature low-pressure two-phase refrigerant, and passes through the indoor heat exchanger 15, The indoor fan 17 evaporates the indoor air while absorbing and cooling the heat, and the accumulator 19 returns the low-temperature low-pressure gas to the variable speed compressor and the constant speed compressor 2.

During heating operation, the refrigerant compressed by both the variable speed compressor 1 and the constant speed compressor 2 or only by the variable speed compressor 1 becomes high temperature high pressure gas. Variable speed compressor 1
When compressed by both the constant speed compressor 2 and the constant speed compressor 2, the refrigerant compressed by the variable speed compressor 1 passes through the variable speed side oil separator 3,
The refrigerant compressed by the constant speed compressor 2 passes through the constant speed side oil separator 4. Further, when compressed only by the variable speed compressor 1, the refrigerant passes only the variable speed side oil separator 3 without reaching the constant speed side oil separator 4 by the check valve 7. in this way,
The refrigerant passing through both or one of the variable speed side oil separator 3 and the constant speed side oil separator 4 passes through the indoor heat exchanger 15 via the four-way valve 9 and exchanges heat with the indoor air by the indoor fan 17. Then, it is condensed while performing radiant heating, becomes a high-pressure liquid refrigerant, passes through the indoor expansion valve 16 and is decompressed by the outdoor expansion valve 11, becomes a low-temperature low-pressure two-phase refrigerant, and the outdoor heat exchanger 10
The outdoor fan 12 absorbs the heat of the outdoor air to evaporate it, and the accumulator 19 returns it to the variable speed compressor 1 and the constant speed compressor 2.

Further, during both the cooling operation and the heating operation, the lubrication contained in both the variable speed compressor 1 and the constant speed compressor 2 or in the high temperature and high pressure refrigerant compressed only by the variable speed compressor 1 The oil is separated by the variable speed side oil separator 3 and the constant speed side oil separator 4 corresponding to each compressor, passes through the variable speed side oil return circuit 5 to the variable speed compressor 1, and again at the constant speed side. The oil is returned to the constant speed compressor 2 via the oil return circuit 6.

[0006]

In such a conventional cooling and heating system, when the variable speed compressor 1 is already started and the constant speed compressor 2 is started, the lubricating oil in the constant speed compressor 2 is immediately after the start. Since a large amount of refrigerant is melted into, the lubricating oil will form. The formed lubricating oil is discharged from the constant-speed compressor 2 and sent to the constant-speed side oil separator 4, but the discharged lubricating oil is in a large amount and is equal to or larger than the capacity of the constant-speed side oil separator 4. Therefore, it overflows and flows out of the outdoor unit 14. As a result, the heat transfer coefficient of the indoor heat exchanger 15 is reduced due to the lubricating oil and the performance is degraded, and the lubricating oil circulates through the indoor unit 18 and returns to the variable speed compressor 1 and the constant speed compressor 2. Since it takes a considerable time to be oiled, the amount of lubricating oil in the variable speed compressor 1 and the constant speed compressor 2 may be less than or equal to the minimum required amount. In the worst case, the compressor is burned. There is also a possibility of causing sticking.

Also, when the variable speed compressor 1 is started, a large amount of refrigerant is dissolved in the lubricating oil in the variable speed compressor 1 immediately after starting, and the lubricating oil is formed. The lubricating oil that has formed is the variable speed compressor 1
Is discharged to the variable speed side oil separator 3 and is discharged to the variable speed side oil separator 3. However, the discharged lubricating oil exceeds the capacity of the variable speed side oil separator 3 and therefore overflows and flows out of the outdoor unit 14. become. Further, since it takes a considerable time for the lubricating oil to circulate through the indoor unit 18 and be returned to the variable speed compressor 1, the amount of lubricating oil in the variable speed compressor 1 may be the minimum required amount or less. There is a possibility that the compressor will burn in the worst case.

Further, when the operating capacity difference between the variable speed compressor 1 and the constant speed compressor 2 is large, the compressor having a higher capacity through the oil equalizing pipe 13 has a larger amount of lubricating oil due to the pressure difference in the outer shell. However, there is a possibility that the amount of lubricating oil in the compressor on the low capacity side will be less than the minimum required amount, and in the worst case, it may cause seizure of the compressor.

The present invention solves the above-mentioned problems. The variable speed compressor 1 is already started and the constant speed compressor 2 is started, or when the variable speed compressor 1 is started, the variable speed compressor 1 is started. The amount of lubricating oil for the machine 1 and the constant speed compressor 2 can be secured,
Further, even when the operating capacity difference between the variable speed compressor 1 and the constant speed compressor 2 is large, it is possible to secure the lubricating oil amount of the compressor on the low capacity side, and to provide a highly reliable air conditioning system. To aim.

[0010]

The present invention according to claim 1 provides a cooling and heating apparatus comprising a variable speed compressor and a constant speed compressor, which are connected in parallel by an oil equalizing pipe and installed in parallel with each other.
A communication pipe that communicates the upstream side of the variable speed oil return circuit with the upstream side of the constant speed oil return circuit, and a check valve that is arranged in the middle of the communication pipe and opens toward the variable speed oil separator. And a variable speed compressor is already started and the constant speed compressor is started, the lubricating oil in the constant speed side oil separator moves to the variable speed side oil separator to reduce overflow. It is a cooling and heating system that is designed to do so.

According to the present invention, when the variable speed compressor is already started and the constant speed compressor is started, the variable speed side oil separator is used together with the constant speed side oil separator to cause an overflow. The amount of lubricating oil flowing out of the outdoor unit is reduced, the lubricating oil of each compressor is secured, and a highly reliable cooling and heating device is obtained.

According to a second aspect of the present invention, in a cooling and heating apparatus including a variable speed compressor and a constant speed compressor, which are connected to each other by an oil equalizing pipe and are installed in parallel with each other, an upstream side of a variable speed oil return circuit is provided. And a constant speed side oil return circuit upstream of the communication pipe, a solenoid valve disposed in the middle of the communication pipe, and a control device for controlling the opening and closing of the solenoid valve, the variable speed compressor or the When the constant speed compressor is activated, the control device opens the solenoid valve for a predetermined time, and the lubricating oil moves between the variable speed side oil separator and the constant speed side oil separator to reduce overflow. It is a cooling and heating system that is designed to do so.

According to the present invention, when the variable speed compressor or the constant speed compressor is started, the variable speed side oil separator and the constant speed side oil separator are used together to reduce the overflow, and the outdoor The outflow of lubricating oil from the machine is reduced, the lubricating oil for each compressor is secured, and a highly reliable cooling and heating device is obtained.

According to a third aspect of the present invention, in a cooling and heating apparatus including a variable speed compressor and a constant speed compressor, which are connected in parallel with each other by an oil equalizing pipe and installed in parallel with each other, the upstream side of the variable speed side oil return circuit is provided. And a communication pipe that communicates with the upstream side of the constant speed side oil return circuit, a solenoid valve arranged in the middle of the communication pipe, a pressure sensor that detects pressure and temperature in the discharge pipe of the constant speed side oil separator, and A temperature sensor and a control device for controlling opening / closing of the solenoid valve are provided, and when the variable speed compressor is started, the control device opens the solenoid valve for a predetermined time,
Further, when the constant speed compressor is activated, the control device opens the solenoid valve, and then detects the superheat degree of the refrigerant in the discharge pipe by the signals of the pressure sensor and the temperature sensor, and the superheat degree is A cooling and heating device in which the solenoid valve is closed when the value exceeds a predetermined value, and lubricating oil moves between the variable speed side oil separator and the constant speed side oil separator to reduce overflow. Is.

According to the present invention, when the variable speed compressor or the constant speed compressor is started, the variable speed side oil separator and the constant speed side oil separator are used together to reduce the overflow, and the outdoor The outflow of lubricating oil from the machine is reduced, the lubricating oil for each compressor is secured, and a highly reliable cooling and heating device is obtained.

According to a fourth aspect of the present invention, in a cooling and heating apparatus including a variable speed compressor and a constant speed compressor, which are connected in parallel with each other by an oil equalizing pipe and are installed in parallel, the upstream side of the variable speed side oil return circuit And a communication pipe that communicates with the upstream side of the constant speed side oil return circuit, and a flow rate control valve arranged in the middle of the communication pipe,
A rotation speed sensor for detecting the rotation speed of the variable speed compressor,
A control device for controlling the opening of the flow rate adjusting valve, when the variable speed compressor or the constant speed compressor is started, the control device fully opens the flow rate adjusting valve for a predetermined time,
The lubricating oil moves between the variable speed oil separator and the constant speed oil separator to reduce overflow, and the variable speed compressor and the constant speed compressor operate simultaneously. When doing so, the control device follows the predetermined relationship between the rotation speed and the opening degree, and when the detected number of rotations is high, decreases the opening degree of the flow rate control valve, and when it is low, increases the opening degree, and The cooling and heating device is configured to increase the amount of oil returned to the low-capacity compressor when the operating capacity difference between the variable-speed compressor and the constant-speed compressor is large.

According to the present invention, when the variable speed compressor or the constant speed compressor is started, the variable speed side oil separator and the constant speed side oil separator are used together to reduce the overflow, and the outdoor. Outflow of lubricating oil from the compressor is reduced, the lubricating oil of each compressor is secured, and when the variable speed compressor and the constant speed compressor operate simultaneously, the variable speed compressor and the The amount of oil returned to the low-capacity compressor increases in response to the difference in operating capacity with the constant-speed compressor, making it easier for the low-pressure compressor to secure lubricating oil.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention as set forth in claim 1, a variable speed compressor and a constant speed compressor, which are communicated with an oil equalizing pipe and installed in parallel with each other, and a discharge side pipe of the variable speed compressor. The variable speed oil separator installed, the constant speed oil separator installed in the discharge side piping of the constant speed compressor, and the lubricating oil stored in the variable speed oil separator are returned to the suction pipe. A variable speed side oil return circuit having a flow rate adjusting function for oiling, a constant speed side oil returning circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed side oil separator to the suction pipe, and a four-way valve An outdoor unit having an outdoor heat exchanger and an outdoor expansion valve, an indoor unit having an indoor heat exchanger and an indoor expansion valve is connected to form an annular refrigerant circuit. , Connecting the upstream side of the variable speed oil return circuit and the upstream side of the constant speed oil return circuit When a communication pipe and a check valve arranged in the middle of the communication pipe and opened in the direction of the variable speed side oil separator are provided, and the variable speed compressor is already started and the constant speed compressor is started. The cooling and heating device is configured so that the lubricating oil in the constant speed oil separator moves to the variable speed oil separator to reduce overflow. Further, according to the present invention as set forth in claim 2, a variable speed compressor and a constant speed compressor, which are connected to each other by an oil equalizing pipe and are installed in parallel with each other, and a variable speed compressor installed in a discharge side pipe of the variable speed compressor. Side oil separator,
A constant speed side oil separator installed in the discharge side pipe of the constant speed compressor, and a variable speed side oil having a flow rate adjusting function of returning the lubricating oil stored in the variable speed side oil separator to the suction pipe. A return circuit, a constant speed oil return circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed oil separator to the suction pipe, a four-way valve, an outdoor heat exchanger, and an outdoor side. An indoor heat exchanger and an indoor unit having an indoor expansion valve are connected to an outdoor unit having an expansion valve to form an annular refrigerant circuit, and the upstream side of the variable speed oil return circuit is connected. And a communication pipe that communicates with the upstream side of the constant speed side oil return circuit, a solenoid valve disposed in the middle of the communication pipe, and a control device that controls opening and closing of the solenoid valve, the variable speed compressor or When the constant speed compressor is started, the control device opens the solenoid valve for a predetermined time. And a heating and cooling device of the lubricating oil is to overflow to move is reduced between the constant speed oil separator and the variable speed oil separator. Further, the present invention according to claim 3 provides a variable speed compressor and a constant speed compressor, which are communicated with an oil equalizing pipe and installed in parallel with each other, and a variable speed compressor installed in a discharge side pipe of the variable speed compressor. A side oil separator, a constant speed side oil separator installed in the discharge side pipe of the constant speed compressor, and a flow rate adjusting function for returning the lubricating oil stored in the variable speed side oil separator to the suction pipe. Variable speed oil return circuit having a constant speed oil return circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed oil separator to the suction pipe, a four-way valve, and an outdoor heat An exchange,
An outdoor unit equipped with an outdoor expansion valve, an indoor heat exchanger,
A communication pipe that connects an indoor unit including an indoor expansion valve to form an annular refrigerant circuit, and connects the upstream side of the variable speed side oil return circuit and the upstream side of the constant speed side oil return circuit A solenoid valve disposed in the middle of the communication pipe, a pressure sensor and a temperature sensor that detect pressure and temperature in the discharge pipe of the constant speed oil separator, and a control device that controls the opening and closing of the solenoid valve. When the variable speed compressor starts, the control device opens the electromagnetic valve for a predetermined time, and when the constant speed compressor starts, the control device opens the electromagnetic valve, The superheat of the refrigerant in the discharge pipe is detected by the signals of the pressure sensor and the temperature sensor, and when the superheat exceeds a predetermined value, the solenoid valve is closed, and the variable speed oil separator and the constant Lubricating oil between high speed oil separator Moving to overflow a heating and cooling apparatus that is reduced. Further, the present invention according to claim 4 is a variable speed compressor and a constant speed compressor, which are connected in parallel with each other through an oil equalizing pipe and are installed in parallel with each other, and a variable speed compressor installed in a discharge side pipe of the variable speed compressor. A side oil separator, a constant speed side oil separator installed in the discharge side pipe of the constant speed compressor, and a flow rate adjusting function for returning the lubricating oil stored in the variable speed side oil separator to the suction pipe. Variable speed oil return circuit having a constant speed oil return circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed oil separator to the suction pipe, a four-way valve, and an outdoor heat An outdoor unit including an exchanger and an outdoor expansion valve is connected to an indoor unit including an indoor heat exchanger and an indoor expansion valve to form an annular refrigerant circuit, and the variable speed side A communication pipe connecting the upstream side of the oil return circuit and the upstream side of the constant speed side oil return circuit; The variable speed compressor is provided with a flow rate control valve disposed in the middle of the communication pipe, a rotation speed sensor for detecting the rotation speed of the variable speed compressor, and a control device for controlling the opening degree of the flow rate control valve. When the constant speed compressor is started, the control device fully opens the flow rate control valve for a predetermined time, and lubricating oil moves between the variable speed side oil separator and the constant speed side oil separator to overflow. When the variable speed compressor and the constant speed compressor are simultaneously operated, the control device follows the predetermined relationship between the rotation speed and the opening degree and detects the detected number of rotations. When the number is high, the opening of the flow control valve is made small, and when it is low, the opening is made large. Cooling and heating to increase the amount of oil returned It is a device.

Hereinafter, embodiments of the present invention will be described. (Embodiment 1) Hereinafter, an embodiment of an air conditioner according to the present invention will be described with reference to the drawings. FIG. 1 is a refrigerant cycle diagram showing the configuration of the cooling and heating device in this embodiment. It should be noted that the same components as those of the conventional example are given the same reference numerals and detailed description thereof will be omitted. In the figure, 20 is a communication pipe that connects the upstream side of the constant speed side oil return circuit 6 and the upstream side of the variable speed side oil return circuit 5, and 21 is an upstream side of the constant speed side oil return circuit 6 in the middle of the communication pipe 20. Is a check valve arranged in a direction in which lubricating oil can flow from the side to the upstream side of the variable speed side oil return circuit 5.

The operation of the above configuration will be described. In addition, the operation of the cooling and heating operation is the same as the conventional example,
Description is omitted. The operation when the variable speed compressor 1 is already started and the constant speed compressor 2 is started will be described. When the constant speed compressor 2 starts up, the variable speed compressor 1 has already started up to perform cooling or heating operation. The constant speed compressor 2 is started when the capacity is insufficient when only the variable speed compressor 1 is operated as the air conditioning load increases. Therefore,
When the constant speed compressor 2 is started, the speed of the variable speed compressor 1 is reduced due to the capacity adjustment accompanying it, and the discharge pressure of the variable speed compressor 1 is reduced. At this time, the refrigerant discharged from the constant speed compressor 2 containing a large amount of lubricating oil flows into the constant speed side oil separator 4 and also passes through the check valve 21 and the variable speed side oil return circuit 5. As a result, the amount of lubricating oil stored in the constant speed side oil separator 4 is reduced and the overflow is reduced. After that, the discharge pressures of the constant speed compressor 2 and the variable speed compressor 1 are balanced and the check valve 21 is closed.

With the above operation, when the variable speed compressor 1 is already started and the constant speed compressor 2 is started, the constant speed side oil separator 4 and the variable speed side oil separator 3 are connected via the check valve. When used together, the lubricating oil in the constant speed side oil separator 4 moves to the variable speed side oil separator 3 to reduce overflow, so that the outdoor unit 1
It is possible to reduce the outflow of lubricating oil from No. 4, secure the amount of lubricating oil in the variable speed compressor 1 and the constant speed compressor 2, and realize a highly reliable cooling and heating device.

(Embodiment 2) Hereinafter, an embodiment of an air conditioner according to the present invention will be described with reference to the drawings. FIG. 2 is a refrigerant cycle diagram showing the configuration of the cooling and heating device in this embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. In the figure, reference numeral 22 is a solenoid valve arranged so that the lubricating oil can flow in both directions in the communication pipe 20, and 30a is a control device for opening and closing the solenoid valve 22.

The operation of the above configuration will be described. The description of the heating and cooling operation will be omitted.

When the variable speed compressor 1 is started, the control device 30a opens the solenoid valve 22 at the same time as it is started. At this time, the refrigerant discharged from the variable speed compressor 1 including the lubricating oil flows into the variable speed side oil separator 3 and the solenoid valve 2
2 flows into the constant speed side oil separator 4 via 2 and the constant speed side oil return circuit 6, so that the amount of lubricating oil stored in the variable speed side oil separator 3 is reduced and the overflow amount is reduced. Will be reduced. Then, the solenoid valve 22 is closed by the control device 30a after a predetermined time.

When the constant speed compressor 2 starts up, the variable speed compressor 1 has already started up to perform cooling or heating operation. Immediately after the constant speed compressor 2 is started, the discharge speed of the variable speed compressor 1 is slightly decreased because the speed of the variable speed compressor 1 is decreased due to the adjustment of the driving capacity. At this time, the refrigerant discharged from the constant speed compressor 2 containing a large amount of lubricating oil flows into the constant speed side oil separator 4 and also passes through the solenoid valve 22 and the variable speed side oil return circuit 5. Since it flows into the variable speed side oil separator 3, the amount of lubricating oil stored in the constant speed side oil separator 4 is reduced, and the overflow amount is reduced. Then, the solenoid valve 22 is closed by the control device 30a after a fixed time.

When the variable speed compressor 1 or the constant speed compressor 2 is started by the above operation, the variable speed side oil separator 3 and the constant speed side oil separator 4 are used together via the solenoid valve 22,
Since the lubricating oil moves between the variable speed side oil separator 3 and the constant speed side oil separator 4 to reduce the overflow, the outdoor unit 1
It is possible to reduce the outflow of lubricating oil from No. 4, secure the amount of lubricating oil in the variable speed compressor 1 and the constant speed compressor 2, and realize a highly reliable cooling and heating device.

(Embodiment 3) Hereinafter, an embodiment of an air conditioner according to the present invention will be described with reference to the drawings. FIG. 3 is a refrigerant cycle diagram showing the configuration of the cooling and heating device in this embodiment. The same components as those in the first and second embodiments are denoted by the same reference numerals, and the detailed description is omitted. In the figure, reference numeral 22 is a solenoid valve arranged in the middle of the communication pipe 20 so that the lubricating oil can flow in both directions. 23 is a pressure sensor, 24 is a temperature sensor, 3
Reference numeral 0b is a control device for opening and closing the solenoid valve 22.

The operation of the above configuration will be described. The description of the operation of the cooling and heating operation is omitted.

When the variable speed compressor 1 is started, the control device 30b opens the solenoid valve 22 at the same time as it is started. At this time, the refrigerant discharged from the variable speed compressor 1 including the lubricating oil flows into the variable speed side oil separator 3 and the solenoid valve 2
2 flows into the constant speed side oil separator 4 via 2 and the constant speed side oil return circuit 6, so that the amount of lubricating oil stored in the variable speed side oil separator 3 is reduced and the overflow amount is reduced. Will be reduced. Then, the solenoid valve 22 is closed by the control device 30b after a fixed time.

When the constant speed compressor 2 starts up, the variable speed compressor 1 has already started up to perform cooling or heating operation. Immediately after the constant-speed compressor 2 is started, the speed of the variable-speed compressor decreases, so the discharge pressure of the variable-speed compressor 1 decreases slightly. At this time, the refrigerant discharged from the constant speed compressor 2 containing a large amount of lubricating oil flows into the constant speed side oil separator 4 and also passes through the solenoid valve 22 and the variable speed side oil return circuit 5. Since it flows into the variable speed side oil separator 3, the amount of lubricating oil stored in the constant speed side oil separator 4 is reduced, and the overflow amount is reduced. Then, the control device 30b calculates the degree of superheat of the refrigerant discharged from the constant speed compressor 2 based on the pressure and temperature detected by the pressure sensor 23 and the temperature sensor 24, and when the temperature exceeds a certain value, lubrication in the refrigerant is performed. The solenoid valve 22 is closed when it is judged that the amount of oil has become small.

When the variable speed compressor 1 or the constant speed compressor 2 is started by the above operation, the variable speed side oil separator 3 and the constant speed side oil separator 4 are used together via the solenoid valve 22,
Since the lubricating oil moves between the variable speed side oil separator 3 and the constant speed side oil separator 4 to reduce the overflow, the outdoor unit 1
It is possible to reduce the outflow of lubricating oil from No. 4, secure the amount of lubricating oil in the variable speed compressor 1 and the constant speed compressor 2, and realize a highly reliable cooling and heating device.

(Embodiment 4) Hereinafter, an embodiment of an air conditioner according to the present invention will be described with reference to the drawings. FIG. 4 is a refrigerant cycle diagram showing the configuration of the cooling and heating device in this embodiment. The same components as those in the first to third embodiments are designated by the same reference numerals and detailed description thereof will be omitted. In the figure, 25 is a flow rate adjusting valve arranged so that the lubricating oil can flow bidirectionally in the middle of the communication pipe 20, 26 is a rotation speed sensor for detecting the rotation speed of the variable speed compressor 1, and 30c is a flow rate adjusting valve. 25 for variable speed compressor 1
It is a control device that adjusts the opening degree according to the number of rotations.

The operation of the above configuration will be described. Further, the description of the cooling / heating operation will be omitted.

When the variable speed compressor 1 is started, the controller 30c opens the flow rate adjusting valve 25 at the same time as it is started. At this time, the refrigerant discharged from the variable speed compressor 1 containing a large amount of lubricating oil flows into the variable speed side oil separator 3 and also passes through the flow rate adjusting valve 25 and the constant speed side oil return circuit 6. As a result, the amount of lubricating oil stored in the variable speed side oil separator 3 is reduced and the overflow amount is reduced. Then, the solenoid valve 22 is closed by the control device 30c after a fixed time.

When the constant speed compressor 2 is started, the variable speed compressor 1 is already started and is performing cooling or heating operation. Immediately after the constant speed compressor 2 is started, the speed of the variable speed compressor 1 decreases, so the discharge pressure of the variable speed compressor 1 decreases slightly. At this time, the refrigerant discharged from the constant speed compressor 2 including a large amount of lubricating oil flows into the constant speed side oil separator 4 and the flow rate adjusting valve 25 and the variable speed side oil return circuit 5 are connected.
Since it flows into the variable speed side oil separator 3 via and, the amount of lubricating oil stored in the constant speed side oil separator 4 is reduced and the overflow amount is reduced. At this time, the control device 30c compares the rotation speed of the variable speed compressor 1 detected by the rotation speed sensor 26 with the rotation speed of the constant speed compressor 2, and the opening degree of the flow rate adjusting valve 25 corresponds to the rotation speed. Adjust according to the table described above. That is, when the rotation speed of the variable speed compressor 1 is smaller than that of the constant speed compressor 2, the lubricating oil flows into the constant speed compressor 2 through the oil equalizing pipe 13, but the opening degree of the flow rate adjusting valve 25 is increased. Then, the lubricating oil stored in the constant speed side oil separator 4 is moved to the variable speed side oil separator 3 to increase the amount of oil returned to the variable speed compressor 1 to lubricate the variable speed compressor 1. The amount of oil is secured, and the opening of the flow rate adjusting valve 25 is reduced as the number of rotations of the variable speed compressor 1 is increased to reduce the amount of movement of the lubricating oil.

When the variable speed compressor 1 or the constant speed compressor 2 is started by the above operation, the variable speed side oil separator 3 and the constant speed side oil separator 4 are used together via the flow rate adjusting valve 25. Since the lubricating oil moves between the variable speed side oil separator 3 and the constant speed side oil separator 4 to reduce the overflow, it is possible to reduce the outflow of the lubricating oil from the outdoor unit 14 and to lubricate each compressor. Oil can be secured, and even when the variable speed compressor 1 and the constant speed compressor 2 are simultaneously operating and the operating capacity difference between the variable speed compressor 1 and the constant speed compressor 2 is large, the low capacity side By increasing the amount of oil returned to the compressor, it is possible to easily secure the lubricating oil in the variable speed compressor 1 and the constant speed compressor 2, and it is possible to realize a highly reliable cooling and heating device.

[0037]

According to the first aspect of the present invention, there is provided a cooling and heating apparatus including a variable speed compressor and a constant speed compressor, which are connected in parallel with each other through an oil equalizing pipe and installed in parallel with each other.
A communication pipe that communicates the upstream side of the variable speed oil return circuit with the upstream side of the constant speed oil return circuit, and a check valve that is arranged in the middle of the communication pipe and opens toward the variable speed oil separator. And a variable speed compressor is already started and the constant speed compressor is started, the lubricating oil in the constant speed side oil separator moves to the variable speed side oil separator to reduce overflow. By doing so, when the variable speed compressor is already started and the constant speed compressor is started, the variable speed side oil separator is used in combination with the constant speed side oil separator, The lubricating oil in the side oil separator is moved to the variable speed side oil separator to reduce the overflow, the outflow of the lubricating oil from the outdoor unit is reduced, and the lubricating oil of each compressor is secured,
A reliable air conditioner can be obtained. According to a second aspect of the present invention, there is provided a cooling and heating apparatus of the present invention, comprising a variable speed compressor and a constant speed compressor, which are connected in parallel with each other by an oil equalizing pipe and are installed in parallel with each other. A communication pipe that connects the upstream side and the constant speed side oil return circuit upstream side;
An electromagnetic valve disposed in the middle of the communication pipe and a control device for controlling the opening / closing of the electromagnetic valve, and when the variable speed compressor or the constant speed compressor is activated, the control device sets the electromagnetic valve to a predetermined value. The variable speed compressor or the constant speed compressor is opened for a period of time so that the lubricating oil moves between the variable speed side oil separator and the constant speed side oil separator to reduce overflow. Is started, the variable speed oil separator and the constant speed oil separator are used together, and the lubricating oil moves between the variable speed oil separator and the constant speed oil separator. The overflow is reduced, the outflow of the lubricating oil from the outdoor unit is reduced, the lubricating oil of each compressor is secured, and a highly reliable cooling and heating device is obtained. According to a third aspect of the present invention, there is provided a cooling and heating apparatus including a variable speed compressor and a constant speed compressor, which are connected in parallel with each other through an oil equalizing pipe and installed in parallel with each other. A communication pipe that connects the upstream side and the upstream side of the constant speed side oil return circuit, a solenoid valve arranged in the middle of the communication pipe, and a pressure that detects the pressure and temperature in the discharge pipe of the constant speed side oil separator. A sensor and a temperature sensor, and a control device that controls opening and closing of the electromagnetic valve, and when the variable speed compressor is activated, the control device opens the electromagnetic valve for a predetermined time, and the constant speed compressor. When the control device opens the solenoid valve, the control device detects the degree of superheat of the refrigerant in the discharge pipe by the signals of the pressure sensor and the temperature sensor, and the degree of superheat exceeds a predetermined value. To close the solenoid valve The variable speed compressor or the constant speed compressor is started by allowing the lubricating oil to move between the variable speed side oil separator and the constant speed side oil separator to reduce the overflow. At this time, the variable speed oil separator and the constant speed oil separator are used together, and the lubricating oil moves between the variable speed oil separator and the constant speed oil separator to reduce overflow. As a result, the amount of lubricating oil flowing out from the outdoor unit is reduced, the lubricating oil for each compressor is secured, and a highly reliable cooling and heating device is obtained. According to a fourth aspect of the present invention, there is provided a cooling and heating apparatus according to the present invention, which includes a variable speed compressor and a constant speed compressor which are connected in parallel with each other by an oil equalizing pipe and are installed in parallel with each other. A communication pipe communicating between the upstream side and the upstream side of the constant speed oil return circuit, a flow rate control valve arranged in the middle of the communication pipe, a rotation speed sensor for detecting the rotation speed of the variable speed compressor, and A control device for controlling the opening of the flow rate adjusting valve, and when the variable speed compressor or the constant speed compressor is started, the control device fully opens the flow rate adjusting valve for a predetermined time, and the variable speed side oil When the lubricating oil moves between the separator and the constant speed oil separator to reduce overflow, and when the variable speed compressor and the constant speed compressor are simultaneously operated,
According to a predetermined relationship between the rotational speed and the opening degree, the control device decreases the opening degree of the flow rate control valve when the detected rotational speed is high, and increases the opening degree when the detected rotational speed is low,
The variable speed compressor or the constant speed compressor is controlled by increasing the amount of oil returned to the low capacity side compressor when the operating capacity difference between the variable speed compressor and the constant speed compressor is large. Is started, the variable speed oil separator and the constant speed oil separator are used together, and the lubricating oil moves between the variable speed oil separator and the constant speed oil separator. Overflow is reduced, the amount of lubricating oil flowing out from the outdoor unit is reduced, the lubricating oil of each compressor is secured, and when the variable speed compressor and the constant speed compressor are operated at the same time, When the operating capacity difference between the variable speed compressor and the constant speed compressor is large, the amount of oil returned to the low-capacity compressor increases, making it easier for the low-pressure compressor to secure lubricating oil. I have to.

[Brief description of drawings]

FIG. 1 is a refrigerant cycle diagram showing a configuration of an embodiment of a cooling and heating apparatus of the present invention according to claim 1.

FIG. 2 is a refrigerant cycle diagram showing the configuration of an embodiment of the cooling and heating apparatus of the present invention according to claim 2;

FIG. 3 is a refrigerant cycle diagram showing the configuration of an embodiment of the cooling and heating apparatus of the present invention according to claim 3;

FIG. 4 is a refrigerant cycle diagram showing the configuration of an embodiment of the cooling and heating apparatus of the present invention according to claim 4;

FIG. 5 is a refrigerant cycle diagram showing a configuration of a conventional cooling and heating device.

[Explanation of symbols]

 1 variable speed compressor 2 constant speed compressor 3 variable speed side oil separator 4 constant speed side oil separator 5 variable speed side oil return circuit 6 constant speed side oil return circuit 9 four-way valve 10 outdoor heat exchanger 11 outdoor side Expansion valve 13 Oil equalizing pipe 14 Outdoor unit 15 Indoor side heat exchanger 16 Indoor expansion valve 18 Indoor unit 20 Communication pipe 21 Check valve 22 Electromagnetic valve 23 Pressure sensor 24 Temperature sensor 25 Flow rate control valve 26 Rotation speed sensor 30a, 30b, 30c control device

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Michimi Kusaka Inventor Matsushita Refrigeration Co., Ltd. 4-5-2, Takaidahondori, Higashiosaka City, Osaka

Claims (4)

[Claims] 1. A variable speed compressor and a constant speed compressor, which are connected in parallel with each other through an oil equalizing pipe and are installed in parallel with each other, a variable speed side oil separator installed in a discharge side pipe of the variable speed compressor, and A constant speed side oil separator installed in the discharge side pipe of the constant speed compressor, and a variable speed side oil return having a flow rate adjusting function for returning the lubricating oil stored in the variable speed side oil separator to the suction pipe. Circuit, a constant speed oil return circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed oil separator to the suction pipe, a four-way valve, an outdoor heat exchanger, and an outdoor expansion An outdoor unit having a valve, an indoor heat exchanger, and an indoor unit having an indoor expansion valve are connected to form an annular refrigerant circuit, and an upstream side of the variable speed oil return circuit A communication pipe that communicates with the upstream side of the constant speed side oil return circuit, and is arranged in the middle of the communication pipe And a check valve that opens toward the variable speed side oil separator, and when the constant speed compressor is started after the variable speed compressor has been started, lubrication in the constant speed side oil separator is performed. A cooling and heating device in which oil moves to the variable speed oil separator to reduce overflow. 2. A variable speed compressor and a constant speed compressor, which are connected in parallel with each other by an oil equalizing pipe and are installed in parallel with each other, a variable speed side oil separator installed in a discharge side pipe of the variable speed compressor, A constant speed side oil separator installed in the discharge side pipe of the constant speed compressor, and a variable speed side oil return having a flow rate adjusting function for returning the lubricating oil stored in the variable speed side oil separator to the suction pipe. Circuit, a constant speed oil return circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed oil separator to the suction pipe, a four-way valve, an outdoor heat exchanger, and an outdoor expansion An outdoor unit having a valve, an indoor heat exchanger, and an indoor unit having an indoor expansion valve are connected to form an annular refrigerant circuit, and an upstream side of the variable speed oil return circuit A communication pipe that communicates with the upstream side of the constant speed side oil return circuit, and is arranged in the middle of the communication pipe When the variable speed compressor or the constant speed compressor is started, the control device opens the electromagnetic valve for a predetermined time, and the variable speed control device controls the opening and closing of the electromagnetic valve. A cooling and heating device in which lubricating oil moves between the side oil separator and the constant speed side oil separator to reduce overflow. 3. A variable speed compressor and a constant speed compressor, which are connected in parallel with each other by an oil equalizing pipe and are installed in parallel with each other, a variable speed side oil separator installed in a discharge side pipe of the variable speed compressor, A constant speed side oil separator installed in the discharge side pipe of the constant speed compressor, and a variable speed side oil return having a flow rate adjusting function for returning the lubricating oil stored in the variable speed side oil separator to the suction pipe. Circuit, a constant speed oil return circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed oil separator to the suction pipe, a four-way valve, an outdoor heat exchanger, and an outdoor expansion An outdoor unit having a valve, an indoor heat exchanger, and an indoor unit having an indoor expansion valve are connected to form an annular refrigerant circuit, and an upstream side of the variable speed oil return circuit A communication pipe that communicates with the upstream side of the constant speed side oil return circuit, and is arranged in the middle of the communication pipe When the variable speed compressor is started, the electromagnetic valve, a pressure sensor and a temperature sensor that detect pressure and temperature in the discharge pipe of the constant speed separator, and a control device that controls opening and closing of the electromagnetic valve are provided. The controller opens the electromagnetic valve for a predetermined time, and when the constant speed compressor is activated, the controller opens the electromagnetic valve, and then the signals of the pressure sensor and the temperature sensor are used to Lubricating between the variable speed side oil separator and the constant speed side oil separator by detecting the degree of superheat of the refrigerant in the discharge pipe and closing the solenoid valve when the degree of superheat exceeds a predetermined value. A cooling and heating device that reduces the overflow of oil by moving oil. 4. A variable speed compressor and a constant speed compressor, which are connected in parallel to each other by an oil equalizing pipe and are installed in parallel with each other, a variable speed side oil separator installed in a discharge side pipe of the variable speed compressor, and A constant speed side oil separator installed in the discharge side pipe of the constant speed compressor, and a variable speed side oil return having a flow rate adjusting function for returning the lubricating oil stored in the variable speed side oil separator to the suction pipe. Circuit, a constant speed oil return circuit having a flow rate adjusting function for returning the lubricating oil stored in the constant speed oil separator to the suction pipe, a four-way valve, an outdoor heat exchanger, and an outdoor expansion An outdoor unit having a valve, an indoor heat exchanger, and an indoor unit having an indoor expansion valve are connected to form an annular refrigerant circuit, and an upstream side of the variable speed oil return circuit A communication pipe that communicates with the upstream side of the constant speed side oil return circuit, and is arranged in the middle of the communication pipe A variable speed compressor, a rotation speed sensor that detects the rotation speed of the variable speed compressor, and a control device that controls the opening degree of the flow rate adjustment valve, and the variable speed compressor or the constant speed compressor is When starting, the control device fully opens the flow rate control valve for a predetermined time so that the lubricating oil moves between the variable speed side oil separator and the constant speed side oil separator to reduce overflow. In addition, when the variable speed compressor and the constant speed compressor operate simultaneously, the control device follows the predetermined relationship between the rotation speed and the opening degree, and the flow rate when the detected rotation speed is high. When the opening of the control valve is small, the opening is large when it is low, and the amount of oil returned to the low-capacity compressor increases when the operating capacity difference between the variable speed compressor and the constant speed compressor is large. Air-conditioning system designed to do.