JPH05196283A - Method of operating heat pump - Google Patents

Abstract

PURPOSE:To continue operation of an air conditioner and to prevent excessive deterioration of air conditioning feeling when abnormal state in each of an inverter, a variable displacement type compressor and its driving motor is detected and any abnormal states are not found in other components. CONSTITUTION:When abnormal state of each of an inverter 21, a variable displacement type compressor 6 and its driving motor 25 is detected, a magnet switch 23 is turned OFF to shut off an electrical supplying to the inverter 21 and at the same time a magnet switch 22 is turned ON to operate a constant displacement type compressor 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a heat pump such as an air conditioner, a refrigerator, a water heater and a dryer.

[0002]

2. Description of the Related Art An example of a refrigerant circuit of a conventional air conditioner is shown in FIG. An outdoor unit 1 includes a constant capacity compressor 5, a variable capacity compressor 6 driven via an inverter, a four-way switching valve 7, an accumulator 8, an outdoor heat exchanger 12, an outdoor blower 13. And so on.

2A, 2B, and 2C are indoor units, among which are indoor heat exchangers 9A, 9B, and 9C, and an indoor blower 10A, respectively.
, 10B, 10C, electronic expansion valves 11A, 11B, 11C, etc. are incorporated. The indoor units 2A, 2B, 2C are connected in parallel to the indoor unit 1 via refrigerant pipes 3A, 3B, and the constant capacity compressor 5 and the variable capacity compressor 6 are connected in parallel in the refrigerant circuit. It is connected.

However, during the cooling operation of each of the indoor units 2A, 2B, 2C, the gas refrigerant discharged from the constant capacity type compressor 5 and the variable capacity type compressor 6 merge and pass through the four-way switching valve 7 to generate outdoor heat. It enters the exchanger 12 and radiates heat to the outside air blown by the outdoor blower 13 to be condensed and liquefied. This liquid refrigerant flows in parallel to each indoor unit 2A, 2B, 2C through the refrigerant pipe 3A, and is adiabatically expanded by being throttled when passing through its electronic expansion valves 11A, 11B, 11C to form a gas-liquid two-phase. It becomes the refrigerant of. Next, this refrigerant enters the indoor heat exchangers 9A, 9B, 9C, where it evaporates by cooling the indoor air blown by the indoor blowers 10A, 10B, 10C. This gas refrigerant returns to the outdoor unit 1 through the refrigerant pipe 3B,
It branches via a four-way switching valve 7 and an accumulator 8 and is sucked into a constant capacity compressor 5 and a variable capacity compressor 6.

During the heating operation of each indoor unit 2A, 2B, 2C, the four-way switching valve 7 is switched in the opposite manner to the above cooling operation. Thus, the refrigerant discharged from the constant capacity compressor 5 and the variable capacity compressor 6 has a four-way switching valve 7, a refrigerant pipe 3B, indoor heat exchangers 9A, 9B, 9C, electronic expansion valves 11A, 11B, 11C,
The refrigerant pipe 3A, the outdoor heat exchanger 12, the four-way switching valve 7, and the accumulator 8 are returned in this order to the compressors 5 and 6.

The flow rate of the refrigerant flowing through the indoor heat exchangers 9A, 9B, 9C is increased or decreased by adjusting the openings of the electronic expansion valves 11A, 11B, 11C according to the loads of the indoor units 2A, 2B, 2C. .. When any one or two of the indoor units 2A, 2B, 2C is deactivated, the electronic expansion valve is fully closed.

Then, as the amount of refrigerant circulating in the refrigerant circuit decreases, the capacity of the variable displacement compressor 6 is gradually reduced by reducing the frequency of the inverter as shown in FIG. 3, and then the constant displacement compression is performed. At the same time when the machine 5 is stopped, only the variable capacity compressor 6 is operated at the maximum capacity, and the capacity of the variable capacity compressor 6 is gradually reduced as the refrigerant circulation amount further decreases.

[0008]

In the above conventional air conditioner, not only when a high pressure switch for detecting a high pressure and a low pressure switch for detecting a low pressure in the refrigerant circuit are activated, but also when an overcurrent flows through the inverter. Even when the inverter or the inverter is overheated, the power supply to the constant capacity compressor 5 and the variable capacity compressor 6 was cut off and the air conditioner was abnormally stopped. Therefore, the constant capacity compressor 5 and the refrigerant circuit have no problem. Although there is no abnormality, there was a problem that the air conditioning feeling was significantly deteriorated due to the abnormal stop of the air conditioner.

[0009]

The present invention has been invented to solve the above-mentioned problems, and its gist is to provide a variable capacity type driven through a constant capacity type compressor and an inverter. In a heat pump consisting of a compressor connected in parallel in a refrigerant circuit, when any abnormality is detected in the inverter, variable displacement compressor and its drive motor, the power supply to the inverter is cut off and the constant capacity is maintained. A method of operating a heat pump is characterized by operating a die compressor.

[0010]

In the present invention, because of the above configuration, when an abnormality is detected in any of the inverter, the variable displacement compressor and its drive motor, the power supply to the inverter is cut off and at the same time the constant displacement compressor is cut off. To drive.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENT An example of an electrical control circuit used to carry out the method of the present invention is shown in FIG. The refrigerant circuit is shown in FIG.
It is similar to the conventional one shown in. A motor 20 and an inverter 21 for driving the constant capacity compressor 5 are connected in parallel to a commercial power supply 24 via magnet switches 22 and 23. The current whose frequency is adjusted by the inverter 21 is the motor 25
To the variable capacity compressor 6 by this motor 25.
Is driven. By increasing or decreasing the inverter frequency, the rotation speed of the motor 25 is increased or decreased, and accordingly, the capacity of the variable displacement compressor 6, that is, the refrigerant discharge amount is increased or decreased.

Constant capacity compressor 5, motor 20, inverter
21, sensors 26, 27, 28, 29, 30 for detecting the abnormality are attached to the variable displacement compressor 6 and the motor 25, respectively, and when these sensors detect the abnormality, the output thereof is sent to the controller 31. Is entered. High pressure switch 32 for detecting high pressure in the refrigerant circuit, low pressure switch 33 for detecting low pressure
Other outputs of the sensors 34, 35, etc. for detecting abnormality of the air conditioner are also input to the controller 31. Then, the magnet switches 22 and 23 are opened and closed according to a command from the controller 31.

However, any abnormality of the inverter 21, the variable displacement compressor 6 or the motor 25 is detected by the sensors 28, 29 and 30, and the other sensors 26, 27, 32, 33, 34 and 35 are detected. When no abnormality is detected, the controller 31 commands the magnet switch 23 to turn it off, and at the same time commands the magnet switch 22 to turn it on. At this time, if the magnet switch 22 is on, it remains on. ..

When an abnormality of the constant capacity compressor 5 or the motor 20 is detected by the sensor 26 or 27, and the other sensors 28 to 35 do not detect the abnormality, the controller 31 commands the magnet switch 22 to turn it off. At the same time, the magnet switch 23 is instructed to turn it ON, and if the magnet switch 23 is ON at this time, it remains ON. Sensor 32-
When 35 or the like detects an abnormality, the controller 31 commands the magnet switches 22 and 23 to turn them off.
Although not shown, when any of the sensors 26 to 30 detects an abnormality, it is desirable to display this or issue an alarm.

However, when the constant capacity compressor 5 and the variable capacity compressor 6 are simultaneously operated and the power supply to the inverter 21 is cut off to stop the variable capacity compressor 6, the capacity of the outdoor unit 1 is lowered. However, when the number of operating indoor units 2A, 2B, 2C is small or the load is small, the air-conditioning capacity is slightly reduced. When the operation of the die compressor 5 is started, the air conditioning capacity is increased.

[0016]

According to the present invention, when an abnormality is detected in any of the inverter, the variable displacement compressor and its drive motor, the power supply to the inverter is cut off. It is possible to prevent damage to the motor. Then, since the constant capacity compressor is operated at the same time when the power supply to the inverter is cut off, the operation of the heat pump can be continuously continued.

[Brief description of drawings]

FIG. 1 is an electrical control circuit diagram used to carry out the method of the present invention.

FIG. 2 is a refrigerant circuit diagram of a conventional air conditioner.

FIG. 3 is a diagram showing a relationship between a refrigerant circulation amount of an air conditioner and a capacity of a compressor.

[Explanation of symbols]

 5 Constant capacity compressor 21 Inverter 6 Variable capacity compressor 25 Motors 28, 29, 30 Abnormality detection sensor 22, 23 Magnet switch 24 Commercial power supply 31 Controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masahiko Sakura Inventor Masahiko Sasaki 3-chome, Asahicho, Nishibiwajima-cho, Nishikasugai-gun, Aichi Mitsubishi Heavy Industries, Ltd. Air Conditioning Factory

Claims (1)

[Claims] 1. A heat pump in which a constant capacity compressor and a variable capacity compressor driven via an inverter are connected in parallel in a refrigerant circuit, wherein the inverter, the variable capacity compressor and its drive motor are When any of the abnormalities is detected, the constant capacity compressor is operated at the same time as the power supply to the inverter is cut off.