JPH0814446B2 - Refrigerant compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a valve portion damage and a bearing of a refrigerant compressor based on "refrigerant liquid return" from a device side to a compressor and "refrigerant stagnation" to refrigerating machine oil. The present invention relates to a refrigerant compressor designed to protect against damage.

[Conventional technology]

Conventionally, as a protective device in this type of refrigerant compressor,
It is well known that an accumulator is mainly installed for "refrigerant liquid return", and an oil heater is mainly arranged for "refrigerant stagnation".

FIG. 4 is a sectional view of a semi-hermetic reciprocating compressor showing an example of a conventional refrigerant compressor equipped with the above heater, and FIG. 5 is a sectional view showing a capacity control mechanism of this compressor.

In FIG. 4, 1 is an electric motor unit, 2 is an electric motor unit 1.
A compression mechanism part 3 driven by the compression mechanism 3 is a crankcase for accommodating the electric motor part 1 and the compression mechanism part 2, 3a
And 3b are a low pressure chamber and a discharge collecting chamber formed by the crankcase 3, respectively, 4 is a cylinder cover mounted on the crankcase 3, 5 is a discharge chamber formed by the cylinder cover 4, and 6a, 6b. Are valve mechanisms, 7a to 7d
Is a bearing portion, which is a main element portion of the compression mechanism portion 2. Reference numeral 8 is a crank chamber, and a refrigerating machine oil 9 is stored in a lower portion of the crank chamber 8. Reference numeral 10 is an oil pump for supplying the refrigerating machine oil 9 to the bearings 7a to 7d, 11 is an oil heater for heating the refrigerating machine oil 9 when the compressor is stopped, and 12 is mounted on the cylinder cover 4 to control the capacity. This is a solenoid valve as a capacity control mechanism.

In FIG. 5, 13 is a bypass valve for opening and closing the passage between the discharge chamber 5 and the low-pressure chamber 3a by non-excitation and excitation of the solenoid valve 12, and 14 is the discharge collecting chamber 3b to the discharge chamber 5a. It is a check valve to prevent backflow to the.

Next, the operation will be described. FIG. 6 is a solubility curve of Suniso 4GS refrigerator oil and Freon 22 refrigerant. In the figure, point A is a state where the ambient temperature is 24 ° C. and the refrigerator oil 9 is not heated by the oil heater 11 (temperature 24 ° C. and saturation pressure 10
The intersection with Kg / cm ² abs) is shown. Since the amount of the refrigerant dissolved in this state is 100% by weight, the refrigerant liquid is dissolved as much as possible.

As described above, when the compressor is started in a state in which a large amount of the refrigerant liquid is dissolved or mixed in the refrigerating machine oil 9, the pressure in the crank chamber 8 is suddenly lowered, so that the refrigerant liquid causes an evaporation phenomenon accompanied by vigorous bubbling. (Hereinafter referred to as “forming phenomenon”). If this "foaming phenomenon" is large, bubbles enter the compression chamber, generate knocking noise and damage the valve mechanism parts 6a and 6b, and the refrigeration oil 9 accompanies the bubbles and is discharged from the compressor. To be made
The amount of oil in the crank chamber 8 decreases, and the oil supply to the bearings 7a to 7d becomes unstable. Since the lubricating oil at this time is a low-viscosity oily substance diluted with the refrigerant liquid, the bearing portions 7a to 7d may be damaged.

On the other hand, in FIG. 6, the point B has the same ambient temperature (24 ° C.) as the point A, and the refrigerator oil 9 is supplied by the oil heater 11.
State when heated by the amount to raise to 14 ℃ (temperature 38 ℃
And the pressure of 10 Kg / cm ² abs).

In this state, the amount of the dissolved refrigerant is about 24 wt%, and the degree of the above-mentioned “forming phenomenon” is greatly reduced, so that damage to the valve mechanisms 6a and 6b and bearing damage can be avoided.

The conventional capacity control mechanism operates to simply reduce the load on the electric motor 1 at the time of starting and to adjust the capacity of the compressor.

[Problems to be solved by the invention]

As described above, the conventional refrigerant compressor suppresses "refrigerant stagnation" by the oil heater. However, when a large amount of the refrigerant liquid enters the refrigerating machine oil 9, the heater heat amount becomes part of the refrigerant liquid. On the other hand, there is a problem that only the amount of heat of gasification (latent heat of vaporization) is contributed, the temperature rise of the refrigerating machine oil 9 cannot be obtained, and damage to the valve mechanisms 6a and 6b and damage at the time of receiving cannot be avoided.

Further, even when the accumulator, which is a "refrigerant liquid return" avoidance device, is used, the same problem occurs when the refrigerant liquid amount is large.

The present invention has been made to solve the above problems, and even if abnormal "refrigerant stagnation" or "refrigerant liquid return" that cannot be protected by the conventional technology occurs,
An object of the present invention is to obtain a refrigerant compressor equipped with a protection device that can reliably protect the compressor.

[Means for solving problems]

The refrigerant compressor according to the present invention includes a refrigerant liquid detector that detects the amount of refrigerant liquid in the electric motor section, an arithmetic unit that determines whether or not there is an abnormality, and the refrigerant liquid excludes the capacity control operation when there is an abnormality. And a control device for executing the process until it is executed.

[Work]

According to the refrigerant compressor of the present invention, the arithmetic unit determines whether there is an abnormality from the amount of the refrigerant liquid in the electric motor section, and the control unit performs the abnormality processing control based on the determination result.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as those in FIGS. 4 to 5 are denoted by the same reference numerals, and only the parts different from those in FIGS. 4 to 5 will be described.

In the figure, reference numeral 15 is a refrigerant liquid detector mounted by utilizing the wall portion of the crankcase 3 for detecting the amount of refrigerant liquid in the electric motor unit 1. The output signal of the refrigerant liquid detector 15 is calculated. It is designed to be delivered to the device 16. Then, the arithmetic unit 16 evaluates the presence / absence of abnormality by comparing and collating the output of the pressure detector 15 with a preset limit liquid amount value, and sends the result to the control unit 17. It is about to do. The control device 17 receives the output of the arithmetic device 16 to control the excitation or non-excitation of the solenoid valve 12 for capacity control.

FIG. 2 is a diagram showing the pressure condition in the discharge chamber 5, and FIG. 3 is a control flow diagram.

Next, the operation will be described. As described in the prior art, when the "refrigerant stagnation" in the refrigerating machine oil 9 and the electric motor section 1 is large, a severe "forming phenomenon" occurs.
Bubbles containing droplets enter the compression chamber. Then, an abnormally large pressure is generated in the compression chamber and the discharge chamber 5. The pressure inside the discharge chamber 5 is as shown in FIG. _2, where ΔP ₁ indicates the amount of pressure increase during normal operation, and ΔP ₂ indicates during operation when knocking noise is generated due to “refrigerant stagnation”. This is the amount of pressure increase. The presence of the refrigerant liquid, which is the source of such pressure, is detected by the refrigerant liquid detector 15.

Next, the arithmetic unit 16 receives the output of the detector 15 and evaluates the presence / absence of abnormality by comparing and collating this with a preset limit liquid amount, and sends the result to the control unit 17. To do.

Finally, the control device 17 receives the output from the arithmetic device 16, and when there is an abnormality, the solenoid valve 12 is de-excited and the bypass valve 13 shown in FIG. The passage between the chambers 3a is opened to perform the capacity control operation for a certain time. By performing this operation, the pressure increase in the discharge chamber 5 is drastically reduced as shown in ΔP ₃ in FIG.

Although the above is the protection operation against "refrigerant stagnation", in the case of "refrigerant liquid return", since the refrigerant liquid always passes through the electric motor room, the same maintenance measure is activated.

〔The invention's effect〕

As described above, according to the present invention, the preventive maintenance procedure is performed without stopping the operation of the compressor by detecting the amount of the refrigerant liquid in the electric motor chamber. There is an effect that various malfunctions of the compressor due to "return" can be surely prevented, and the enjoyment loss of the customer can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of a refrigerant compressor according to an embodiment of the present invention, FIG. 2 is a diagram showing a state of generation of pressure in a discharge chamber shown in FIG. 1, FIG. 3 is a control flow diagram of the present invention, and FIG. Fig. 5 is a cross-sectional view showing a conventional refrigerant compressor, Fig. 5 is a cross-sectional view showing the capacity control mechanism of this compressor, and Fig. 6 is Suniso 4GS and Freon 22.
It is a solubility curve figure between. 1 is an electric motor part, 2 is a compression mechanism part, 3 is a crankcase,
3a is a low pressure chamber, 3b is a discharge collecting chamber, 4 is a cylinder cover, 5
Is a discharge chamber, 6a and 6b are valve mechanisms, 7a to 7d are bearings, 8 is a crank chamber, 9 is refrigerating machine oil, 10 is an oil pump, 11 is an oil heater, 12 is a solenoid valve, and 15 is a refrigerant liquid detector. , 16 is an arithmetic unit, 17 is a controller. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A compression mechanism portion driven by an electric motor portion, a crankcase for accommodating the electric motor portion and the compression mechanism portion, a cylinder cover for forming a discharge chamber attached to the crankcase, and the cylinder cover. In a refrigerant compressor having a capacity control mechanism mounted on the above for performing capacity control, a refrigerant liquid detector provided on the electric motor side of the crankcase for detecting the amount of refrigerant liquid, and an output signal of this refrigerant liquid detector. And an arithmetic unit for evaluating the presence / absence of abnormality by comparing and collating with a preset limit liquid amount value, and when the abnormality evaluation signal is received from this arithmetic unit, the capacity control mechanism is controlled to eliminate the refrigerant liquid. And a control device that performs a capacity control operation until the above.