JPH08110102A - Preheater for compressor - Google Patents

Abstract

PURPOSE: To shorten the starting time of a compressor by improving the thermal efficiency at the time of preheating when the atmospheric temperature is low and to perform the energy conservation in a horizontal compressor. CONSTITUTION: When two-phase coils 45, 46 of three-phase coils of a three-phase induction motor 16 are connected in phase and a currant flows between the coils 45, 46 and the residual one-phase coil 42, the coil 42 in which its heat generation rate becomes large is disposed in refrigerating machine oil 50 at the bottom of a case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preheating device for a compressor mounted on an air conditioner or the like.

[0002]

2. Description of the Related Art In a compressor installed in an air conditioner, the refrigerant is liquefied at a low outside temperature such as winter, and a large amount of liquid mixed with low temperature lubricating oil is accumulated in the compressor case. If the compressor is operated in this state, a bubbling phenomenon will occur due to the rapid release of the refrigerant in the oil, and at the same time, the lubricating oil will also be carried away, reducing the amount of oil in the compressor and impeding lubrication. Become. Furthermore, when the foaming phenomenon is severe, liquid compression occurs, and this liquid compression is also a major cause of compressor accidents.

As a conventional example for preventing such a problem, for example, there is an apparatus described in Japanese Patent Laid-Open No. 62-258964. In this device, a drive signal lacking one phase is applied to the drive motor of the compressor driven by the three-phase voltage when the operation is stopped, thereby heating the compressor without rotating the drive motor,
The liquid refrigerant mixed in the lubricating oil is vaporized and separated from the lubricating oil to prepare for the start of operation.

[0004]

In the above-mentioned conventional example, the compressor main body is heated to raise the oil temperature, whereby the liquid refrigerant is vaporized and separated from the lubricating oil. However, generally, the heat capacity of the compressor installed in the air conditioner is large, and therefore a large amount of heat is consumed to raise the oil temperature until the liquid refrigerant is vaporized. Therefore, in the above-mentioned conventional example, there are drawbacks that the operation startup time of the compressor becomes long and the energy used for other than the original air conditioning operation becomes large. By the way, from the viewpoint of downsizing the outdoor unit of an air conditioner in recent years, a so-called horizontal compression having a drive motor in which a rotary shaft is horizontally installed and coils are arranged on a circumference surrounding the rotary shaft. Machines are attracting attention. The present invention has been made in order to solve the above-mentioned conventional drawbacks in such a horizontal compressor, and an object thereof is to improve the operation efficiency of the compressor by improving the thermal efficiency during preheating. Shorten,
Another object of the present invention is to provide a preheating device for a compressor that can save energy.

[0005]

Therefore, a preheating device motor shaft 44 for a compressor according to claim 1 is horizontally installed, and a drive motor 1 in which a coil is arranged so as to surround the motor shaft 44.
In the preheating device for a compressor equipped with 6, when heating the refrigerator oil 50 by energizing the coil so as not to rotate the drive motor 16 to heat the refrigerating machine oil 50, the heating coil 42 is collected at the bottom of the compressor case 47. It is characterized in that it is arranged so as to come into contact with the refrigerator oil 50.

The preheating device for a compressor according to claim 2 is
The drive motor 16 is a three-phase induction motor, and of the three-phase coils 42, 45, 46, two-phase coils 45, 46 are included.
Are connected in the same phase, and when a current is passed between the coils 45 and 46 of these two phases and the remaining one-phase coil 42, the remaining one-phase coil 42 is accumulated at the bottom of the compressor case 47. It is characterized in that it is arranged so as to come into contact with the refrigerator oil 50.

Further, in the preheating device for a compressor according to claim 3, the drive motor 16 is a three-phase induction motor, and one of the three-phase coils 42, 45, 46 is separated from the coil 45 of one phase, and the remaining coil is left. When an electric current is passed between the two-phase coils 42 and 46, at least one of the two-phase coils 42 and 46 is arranged so as to come into contact with the refrigerating machine oil 50 accumulated at the bottom of the compressor case 47. It has a feature.

[0008]

In the compressor preheating device according to the first aspect, the heating coil 42 is in contact with the refrigerating machine oil 50 accumulated at the bottom of the compressor case 47. Therefore, the refrigerator oil 50 can be directly heated, and the refrigerant can be efficiently vaporized.

Further, in the preheating device for a compressor according to the second aspect, the coil 42 having the maximum calorific value among the three heating coils 42, 45 and 46 directly heats the refrigerating machine oil 50. Therefore, the preheating efficiency can be further improved.

Further, in the preheating device for a compressor according to claim 3, the refrigerating machine oil 50 is directly heated by using at least one of the two heating coils 42 and 46 having the same calorific value. Therefore, the refrigerant can be efficiently vaporized.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the preheating device for a compressor of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an air conditioner. In the figure, 1 is a compressor, 2 is a four-way switching valve, 3 is an outdoor heat exchanger, 4 is an expansion valve, and 5 is an indoor heat exchanger. Each of these devices 1 to 5 has a refrigerant pipe 6 respectively.
It is connected so that the refrigerant can circulate. During the cooling operation, the four-way switching valve 2 is switched as shown by the solid line in the figure to circulate the refrigerant as shown by the solid line arrow. As a result, the amount of heat absorbed from the room by the indoor heat exchanger 5 is radiated to the outside air by the outdoor heat exchanger 3 to repeatedly cool the room.
On the other hand, during the heating operation, the four-way switching valve 2 is switched as shown by the broken line in the figure to circulate the refrigerant as shown by the broken line arrow. As a result, the transfer of heat is reversed from that during the cooling operation,
Heat the room.

The cooling and heating device incorporating the compressor 1 is
A three-phase commercial power source 10 is connected. An inverter 12 that controls the capacity of the compressor 1 is provided in a power supply circuit of the cooling and heating device. Compressor 1 with this inverter 12
Change the supply voltage value to and the operating frequency. With this, while changing the drive torque of the compressor 1,
The capacity is smoothly increased or decreased according to the air conditioning load so that the air conditioning capacity corresponds to the air conditioning load.

FIG. 2 shows the internal structure of the inverter 12. In the converter unit 15, the AC voltage from the three-phase power supply 10 is converted into DC, and in the inverter unit 17,
The direct current converted by the converter unit 15 is converted into a three-phase alternating current having a voltage value and a frequency value different from the power source voltage and the power source frequency of the commercial power source 10 to drive the compressor 1 (three-phase induction motor). ) 16 is applied. The inverter unit 17 applies six voltages to the compressor driving motor 16 to drive it, and six power transistors Tu, Tv,
Control circuit 1 for ON-OFF controlling Tw, Tx, TY, Tz and the above six power transistors and outputting a V-W coil in-phase connection signal to the drive motor 16.
8 and. Further, the room temperature signal of the room temperature sensor TH for detecting the room temperature provided in the indoor heat exchanger 5 and the state signal of the operation / stop switch 13 are input to the control circuit 18. In addition, 19 in FIG. 2 is a feedback diode.

FIG. 3 shows the internal structure of the control circuit 18. Reference numeral 20 is a microcomputer including a CPU and the like. The microcomputer 20 has a function of outputting a cooling operation command signal or a heating operation command signal depending on the season. Further, the difference between the room temperature signal from the room temperature sensor TH and the room temperature target value (set value), that is, the air conditioning load is calculated, and the inverter unit 17 calculates each command signal of the voltage value and the frequency value according to the air conditioning load. It has a function to generate. Further, it has a function as a stop time detecting means for detecting the stop of the operation, and outputs the V-W coil in-phase connection signal to the drive motor 16 when the stop of the heating operation is detected.

Reference numeral 21 is a three-phase control signal generator which incorporates a ROM, an oscillator, a counter and the like. The three-phase control signal generator 21 produces a continuous three-phase waveform as the three-phase control signal having a voltage value and a frequency corresponding to an air conditioning load in accordance with the voltage command signal and the frequency command signal from the microcomputer 20. 6 power transistors Tu to Tw and Tx to Tz.

FIG. 4 is a schematic sectional view showing the structure of the compressor 1. In the figure, 16 is a compressor drive motor, and 44 is a motor shaft, which are arranged substantially horizontally. Rotor 43
Rotates on a vertical plane orthogonal to the motor shaft 44,
The power is applied to the compression mechanism 41 composed of a piston, a cylinder, etc. via 4. Low-pressure gas refrigerant is suction port 4
After being sucked into the compression mechanism 41 from 0 and compressed, it becomes a high-pressure gas refrigerant, is discharged from the discharge port 39, and circulates in the refrigerant pipe 6. 42 is a U-phase coil. The U-phase coil 42 is connected to the power transistors Tu and Tx, and the inverter 12 supplies the U-phase of the three-phase waveform.

FIG. 5 is a sectional view of the compressor drive motor 16 taken along a vertical plane orthogonal to the motor shaft 44. In the figure, 45 and 45 are W-phase coils, which are connected to the power transistors Tw and Tz of the inverter unit 17. Further, 46 and 46 are V-phase coils, which are connected to the power transistors Tv and TY of the inverter unit 17. Reference numeral 50 indicates the state of the refrigerating machine oil when the operation is stopped. The main component of the refrigerating machine oil 50 is lubricating oil, but it is a mixture of a large amount of liquefied refrigerant at low outside air temperature.

When the operation of the compressor 1 is stopped, the refrigerating machine oil 50 accumulates at the bottom of the compression shield case 47, and U
The phase coil 42 is arranged inside thereof.

In the embodiment having the above-mentioned structure, during the air conditioning operation, the control circuit 18 causes the six power transistors Tu, Tv, Tw, Tx, TY, and Tz to control the voltage value and the frequency according to the air conditioning load. A three-phase control signal is output. As a result, a drive torque corresponding to the supply voltage value of the three-phase waveform applied is generated in the compressor motion motor 16,
The compressor drive motor 16 rotates at a rotation speed according to the supply frequency. As a result, the capacity of the compressor 1 increases and decreases,
It will respond well to the air conditioning load.

On the other hand, when the heating operation is stopped at a low outside air temperature such as in winter, the control circuit 18 connects the V-phase coil and the W-phase coil in the same phase. This allows the U phase and V
A single-phase alternating current of a single phase is applied to the compressor drive motor 16, and the coils generate heat without rotating the compressor drive motor 16.

FIG. 6 shows the situation at this time. In the figure, 16 is a compressor drive motor, 42 is a U-phase coil,
46 indicates a V-phase coil, and 45 indicates a W-phase coil. Further, one end of the W-phase coil 45 is connected in phase with one end of the V-phase coil 46 according to a command from the control circuit 18. Therefore, assuming that the current value flowing through the U-phase coil 42 is I, the current values flowing through the V-phase coil 46 and the W-phase coil 45 are both 1/2. That is, during the above heating, the U-phase coil 42 among the three coils has the maximum amount of heat generation. Then, as shown in FIG.
Since the phase coil 42 is installed inside the refrigerating machine oil 50, the oil 50 can be directly heated by the coil having the maximum calorific value, whereby the refrigerant can be efficiently vaporized and separated from the lubricating oil. it can.

FIG. 7 shows another embodiment of the preheating operation. This is because one end of the W-phase coil 45 is connected to the inverter 1
In step 2, the W-phase waveform is opened to make the open end. In this case, no current flows through the W-phase coil 45. Therefore, assuming that the current value flowing through the U-phase coil 42 is I, the current value flowing through the V-phase coil 46 is also I. Therefore, in this case, the heating coils are the V-phase coil 46 and the U-phase coil 42, and the heating values of both coils are equal. Also in this embodiment, as in the first embodiment, the U
Since the phase coil 42 is installed so as to be in contact with the refrigerating machine oil 50, the refrigerating machine oil 50 can be directly heated by the coil having a heat generation amount of ½ of the whole, whereby the refrigerant is efficiently vaporized and lubricated. Can be separated from oil.

Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, in the first embodiment, the U-phase coil 42 is brought into contact with the refrigerator oil 50, and the V-phase coil 46 and the W-phase coil 4 are connected.
5 are connected in the same phase, but the V phase coil 46 is connected to the refrigerator oil 5
The U-phase coil 42 and the W-phase coil 45 may be connected in phase with each other by bringing them into contact with 0, or the W-phase coil 45 may be brought into contact with the refrigerating machine oil 50 so that the U-phase coil 42 and the V-phase coil 46 are connected in-phase with each other. May be. In addition, in the second embodiment,
The coil in which no current flows in the preheating operation is the V-phase coil 4
The coil installed in contact with the refrigerating machine oil 50 may be the V-phase coil 46 or the W-phase coil as long as the coil is energized in the preheating heating operation. Good. Further, although the three-phase power source 10 is used in each of the above-described embodiments, the single-phase power source may be used.

[0025]

As described above, in the preheating device for a compressor according to the first aspect of the present invention, since the heating coil is in contact with the refrigerating machine oil accumulated at the bottom of the compressor case, the refrigerating machine oil can be directly heated. It is possible to efficiently transfer the generated heat to the refrigerating machine oil. Therefore, the oil temperature can be raised within a short time with a small amount of heat, and a quick warming effect can be obtained at the start of heating operation in the winter and the like. Further, since the amount of heat required for keeping the oil temperature constant may be small, it is possible to save energy.

In the compressor preheating device according to the second aspect of the present invention, the one having the maximum calorific value of the three heating coils directly heats the refrigerating machine oil.
Further, it becomes possible to improve the preheating efficiency. Therefore, the rapid heating effect and energy saving are further improved.

Further, in the compressor preheating device according to the third aspect, the refrigerating machine oil is directly heated by using one of the two heating coils having the same heating value. Also, the preheating efficiency can be improved, and the rapid heating effect and energy saving can be obtained.

[Brief description of drawings]

FIG. 1 is a refrigerant piping system diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is an electric circuit diagram showing an internal configuration of an inverter of the device.

FIG. 3 is a block diagram showing an internal configuration of a control circuit of the device.

FIG. 4 is a schematic sectional view showing a configuration of a compressor of the above apparatus.

FIG. 5 is a schematic sectional view showing a relationship between a coil of a compressor motor of the above apparatus and refrigerating machine oil.

FIG. 6 is a principle diagram illustrating a preheating operation in the first embodiment.

FIG. 7 is a principle diagram illustrating a preheating operation in a second embodiment.

[Explanation of symbols]

 1 Compressor 16 Compressor drive motor 42 U-phase coil 44 Motor shaft 47 Compressor case 50 Refrigerator oil

Claims (3)

[Claims] 1. A preheating apparatus for a compressor, comprising a drive motor (16) in which a motor shaft (44) is installed horizontally and a coil is arranged so as to surround the motor shaft (44). 16) When heating the refrigerator oil (50) by energizing the coil so as not to rotate it and heating the refrigerator oil (50), the heating coil (42) contacts the refrigerator oil (50) accumulated at the bottom of the compressor case (47). A preheating device for a compressor, characterized in that it is arranged as follows. 2. The drive motor (16) is a three-phase induction motor, and two-phase coils (45) (46) of the three-phase coils (42) (45) (46) are connected in phase to each other, When a current is passed between the coils (45) (46) of these two phases and the coil (42) of the remaining one phase, the coil (42) of the remaining one phase is attached to the bottom of the compressor case (47). The preheating device for a compressor according to claim 1, wherein the preheating device is arranged so as to come into contact with the refrigerating machine oil (50) accumulated in. 3. The drive motor (16) is a three-phase induction motor, and the one-phase coil (45) of the three-phase coils (42) (45) (46) is separated to leave the remaining two-phase coils. When a current is passed between the coils (42) and (46), at least one of the two-phase coils (42) and (46) is brought into contact with the refrigerating machine oil (50) accumulated at the bottom of the compressor case (47). The preheating device for the compressor according to claim 1, wherein the preheating device is arranged as follows.