阅读说明：本技术 制冷循环装置 (Refrigeration cycle device ) 是由 前山英明 酒井显 于 2017-12-15 设计创作，主要内容包括：本发明的制冷循环装置具有制热模式和除霜模式作为运转模式。制冷循环装置具备压缩机(10)、第一热交换器和第二热交换器、膨胀阀以及控制装置。压缩机(10)由马达(12)驱动。压缩机(10)储存冷冻机油。控制装置驱动马达(12)。制冷剂(RL1)在制热模式下以压缩机(10)、第一热交换器、膨胀阀以及第二热交换器的顺序循环。制冷剂(RL1)的密度小于冷冻机油(RO1)的密度。在压缩机(10)的内部,在除霜模式下液状的制冷剂(RL1)和冷冻机油(RO1)分离为两层。控制装置使除霜模式下的马达(12)的热损失比制热模式下的热损失增加。(A refrigeration cycle device is provided with a compressor (10), a first heat exchanger, a second heat exchanger, an expansion valve, and a control device, wherein the compressor (10) is driven by a motor (12), the compressor (10) stores refrigerating machine oil, the control device drives the motor (12), a refrigerant (R L1) circulates in the order of the compressor (10), the first heat exchanger, the expansion valve, and the second heat exchanger in the heating mode, the density of the refrigerant (R L1) is lower than that of the refrigerating machine oil (RO1), the refrigerant (R L1) and the refrigerating machine oil (RO1) are separated into two layers in the defrosting mode inside the compressor (10), and the control device increases the heat loss of the motor (12) in the defrosting mode as compared to the heat loss in the heating mode.)

1. A refrigeration cycle apparatus having a heating mode and a defrosting mode as operation modes, wherein,

the refrigeration cycle device is provided with:

a compressor storing refrigerating machine oil and driven by a motor;

a first heat exchanger and a second heat exchanger;

an expansion valve; and

a control device for controlling the motor,

a refrigerant circulates in the order of the compressor, the first heat exchanger, the expansion valve, and the second heat exchanger in the heating mode,

in the compressor, the density of the refrigerant is lower than the density of the refrigerator oil, and the refrigerant in a liquid state is separated from the refrigerator oil into two layers in the defrosting mode,

the control means increases the heat loss of the motor in the defrosting mode more than the heat loss in the heating mode.

2. The refrigeration cycle apparatus according to claim 1,

the compressor includes:

a casing storing the refrigerator oil and housing the motor; and

and a compression mechanism driven by the motor, compressing the refrigerant from a suction port of the compressor, and discharging the compressed refrigerant to a space where the motor is disposed.

3. The refrigeration cycle device according to claim 1 or 2, wherein,

the control device makes a driving voltage of the motor smaller than the driving voltage in the heating mode in the defrosting mode, and delays a phase of an induced electromotive force of the motor from a phase of the driving voltage.

4. The refrigeration cycle device according to claim 1 or 2, wherein,

the control device makes a driving voltage of the motor greater than the driving voltage in the heating mode in the defrosting mode, and advances a phase of an induced electromotive force of the motor more than a phase of the driving voltage.

5. The refrigeration cycle device according to claim 1 or 2, wherein,

the control device drives the motor in synchronization with a carrier frequency, and in the defrosting mode, the carrier frequency is set lower than the carrier frequency in the heating mode.

6. The refrigeration cycle device according to claim 1 or 2, wherein,

the control device drives the motor in the defrosting mode so that the generated torque of the motor follows the load torque of the compressor.

7. The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein,

the refrigerant circulates in a direction opposite to the heating mode in the defrosting mode.

8. The refrigeration cycle device according to any one of claims 1 to 7, wherein,

the refrigerator oil is immiscible with the refrigerant.

9. The refrigeration cycle apparatus according to any one of claims 1 to 8, wherein,

the refrigerant has a polytropic exponent that is less than the polytropic exponent of the HFC refrigerant.

10. The refrigeration cycle apparatus according to claim 9, wherein,

the refrigerant includes HC refrigerant.

11. The refrigeration cycle apparatus according to claim 10,

the refrigerant includes R290.

Technical Field

The present invention relates to a refrigeration cycle apparatus having a defrosting mode as an operation mode.

Background

Conventionally, a refrigeration cycle apparatus having a defrosting mode as an operation mode is known. For example, japanese patent application laid-open No. 59-221543 (patent document 1) discloses an air conditioner including: in the defrosting operation, the driving voltage of the motor of the compressor is reduced from the voltage at which the motor efficiency reaches the maximum value, and the amount of defrosting heat is increased, thereby shortening the time required for defrosting.

Disclosure of Invention

Problems to be solved by the invention

In the defrosting mode, the heat of the refrigerant is used for defrosting, and therefore the heat of the refrigerant sucked into the compressor is usually smaller than usual. In the defrost mode, the refrigerant is easily condensed inside the compressor. When the refrigerating machine oil stored in the compressor is diluted with a liquid refrigerant (liquid refrigerant), the lubricating ability of the refrigerating machine oil is lowered. As a result, the sliding portion of the compressor is more likely to be damaged.

The present invention has been made to solve the above-described problems, and an object thereof is to improve the stability of a refrigeration cycle apparatus.

Means for solving the problems

A refrigeration cycle device has a heating mode and a defrosting mode as operation modes. The refrigeration cycle device is provided with a compressor, a first heat exchanger, a second heat exchanger, an expansion valve, and a control device. The compressor is driven by a motor. The compressor stores refrigerator oil. The control device drives the motor. The refrigerant circulates in the order of the compressor, the first heat exchanger, the expansion valve, and the second heat exchanger in the heating mode. The density of the refrigerant is less than the density of the refrigerator oil. In the compressor, the liquid refrigerant and the refrigerating oil are separated into two layers in the defrosting mode. The control means increases the heat loss of the motor in the defrosting mode compared to the heat loss in the heating mode.

Effects of the invention

According to the refrigeration cycle apparatus of the present invention, by increasing the heat loss of the motor in the defrosting mode as compared to the heat loss of the motor in the heating mode, it is possible to suppress a decrease in the lubricating ability of the refrigerator oil in the interior of the compressor in which the density of the refrigerant is lower than the density of the refrigerator oil and the liquid refrigerant and the refrigerator oil are separated into two layers. As a result, the stability of the refrigeration cycle apparatus can be improved.

Drawings

Fig. 1 is a functional block diagram showing the configuration of a refrigeration cycle apparatus according to embodiment 1.

Fig. 2 is a functional block diagram showing a functional configuration of the motor drive circuit of fig. 1.

Fig. 3 is a graph showing GWP, polytropic index, and theoretical discharge temperature of R32, R410A, and R290, respectively.

Fig. 4 is a graph showing a relationship between a driving voltage of the motor and a motor efficiency when the rotation speed of the motor of fig. 2 is made constant.

Fig. 5 is a diagram showing timing charts of the drive voltage and the induced electromotive force of the motor in the normal mode.

Fig. 6 is a diagram showing timing charts of the drive voltage and the induced electromotive force of the motor in the defrosting mode in embodiment 1.

Fig. 7 is a view showing an internal structure of the compressor of fig. 1.

Fig. 8 is a diagram showing an internal structure of another example of the compressor of the refrigeration cycle apparatus according to embodiment 1.

Fig. 9 is a waveform diagram of a PWM signal in the normal mode of embodiment 3.

Fig. 10 is a waveform diagram of a PWM signal in the defrosting mode of embodiment 3.

Fig. 11 is a timing chart showing the load torque of the compressor, the generation torque of the motor in the normal mode, and the generation torque of the motor in the defrosting mode.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and description thereof will not be repeated in principle.