JPH05231722A - Compressor protector of air conditioning equipment and protection method thereof - Google Patents

Abstract

PURPOSE: To protect a compressor during heating operation under cold region temperature by controlling peripheral units and a two-way valve drive means, based on a detected outer air temperature and introducing liquid refrigerant to an auxiliary accumulator through action of the two-way valve, while filtering the liquid refrigerant so as not allow it to flow into the compressor. CONSTITUTION: Outer air temperature is detected by a temperature sensing means 40 during heating operation. When the outer air temperature is a cold region temperature, a two-way valve 25 passing refrigerant directly to an accumulator 10 is turned off by a two-way valve drive means, such that the refrigerant is passed to both the accumulator 10 and an auxiliary accumulator 20. Consequently, liquid refrigerant produced through two layer separation phenomenon caused by the cold region temperature is subjected to double filtering through the auxiliary accumulator 20 and the accumulator 10 and removed completely, before being circulated to a compressor 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor protection device for an air conditioner and a method for protecting the same, and more particularly, when the air conditioner is operated in a cold region, that is, when the outside air temperature is extremely low. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor protection device for an air conditioner and a protection method thereof, which can prevent a liquid refrigerant from flowing into the compressor by using a heavy-loaded accumulator and can smoothly restore lubricating oil into the compressor.

[0002]

2. Description of the Related Art Generally, as an air conditioner for both heating and cooling, which is used for residential purposes and other purposes, it has been used as an actual air conditioner 61-1248.
An example is shown in Japanese Patent Publication No. 52-52.

As shown in FIG. 5, the air conditioner based on this conventional example comprises a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion device 4 and an indoor heat exchanger 5.

The compressor 1 and the four-way valve 2 are drive-controlled by a compressor drive unit 1a and a four-way valve drive unit 2a based on an output signal of a microcomputer 7 which is a system control means.

The four-way valve 2 is arranged so that the refrigerant flows in the direction of the dotted arrow, and the compressor 1, the four-way valve 2, the outdoor heat exchanger 3,
A cooling cycle is formed in the order of the expansion device 4, the indoor heat exchanger 5, the accumulator 6, and the compressor 1. On the other hand, when power is applied to the drive coil of the four-way valve 2 to switch the flow of the refrigerant in the direction of the solid line arrow, the compressor 1, the four-way valve 2, the indoor heat exchanger 5, the expansion device 4, the outdoor heat exchanger. A heating cycle is formed in the order of 3, the accumulator 6, and the compressor 1.

In an air conditioner that forms a heating cycle, the accumulator filters the liquid refrigerant in the refrigerant circulated to the compressor when the outside air temperature is low (when the load fluctuates), and only the gaseous refrigerant is used. The compressor is protected by being circulated.

[0007]

By the way, when the outside air temperature becomes lower than the cold temperature (-10 ° C. or lower), the double circulation phenomenon of the refrigerant and the oil circulated in the cooling cycle occurs, and the liquid refrigerant increases. Therefore, since one accumulator cannot completely filter the liquid refrigerant in the refrigerant circulated in the compressor, there is a problem that the heating capacity of the air conditioner decreases. Further, since a certain amount of oil is not continuously circulated to the compressor, there is a problem that heat is generated inside the compressor.

Therefore, in order to solve the above problems, an object of the present invention is to install an auxiliary accumulator in addition to the existing accumulator of the air conditioner so that the outside air temperature can be set during heating operation. When the temperature falls below a certain value (cold temperature), the liquid refrigerant that flows into the compressor is completely filtered, and the specified amount of oil is continuously supplied to the compressor. An object is to provide a device and a protection method thereof.

[0009]

In order to achieve the above object, a compressor protection device according to the present invention is installed in a predetermined position of the air conditioner in an air conditioner equipped with a heating system and the outside air temperature is adjusted. Temperature sensing means, system control means for controlling the two-way valve driving means and peripheral devices based on the data output from the temperature sensing means, and liquid refrigerant passing through the accumulator by the operation of the two-way valve and compressed. It consists of an auxiliary accumulator that filters the flow into the machine.

Further, the compressor protection method according to the present invention includes a heating operation determination step of determining whether the air conditioner is equipped with a heating system during heating operation, and a heating operation in the heating operation determination step. If it is determined that the outside temperature is the cold temperature (-10 ° C or less), the temperature of the outside air is judged to be the cold temperature (-10 ° C or less). And a refrigerant flow control step of controlling the flow of the refrigerant so as to flow into the compressor after passing through the auxiliary accumulator and the accumulator.

According to the present invention configured as described above,
When the current data value of the outside air temperature sensed by the temperature sensing means is a cold temperature (-10 ° C. or less), the refrigerant in the liquid state is allowed to pass through the accumulator and the auxiliary accumulator, so that a certain amount of the liquid refrigerant is cooled. Is filtered by the auxiliary accumulator. Therefore, only the optimum amount of refrigerant required for heating operation will be supplied to the compressor,
The heating operation can be performed in the most suitable state.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a compressor protection device for an air conditioner according to the present invention has a two-way valve between a four-way valve 30 and an accumulator 10 for changing the flow of refrigerant in accordance with cooling and heating operation. A two-way valve 25 operated by the one-way valve driving means 40b is provided, and an inlet and an outlet of the auxiliary accumulator 20 are connected to front and rear ends of the two-way valve 25, respectively.

Further, the two-way valve driving means 40b is connected so that its operation is controlled by the system control means 40a which controls the peripheral system according to the output signal of the temperature sensing means 40 which senses the outside air temperature. ing.

FIG. 3 shows another embodiment of the present invention. In the compressor protection device for an air conditioner of this embodiment, the compressor 5 is used.
A two-way valve 25 operated by a two-way valve drive means 40b is provided between the suction port of 0 and the outlet of the accumulator 10, and the inlet and outlet of the auxiliary accumulator 20 are provided at the front and rear ends of the two-way valve 25. And the exit are connected respectively.

The two-way valve driving means 40b is attached to the body portion of the accumulator 10 through the system control means 40a for controlling the peripheral system according to the output signal of the temperature sensing means 40 for sensing the outside air temperature. Connected in a controlled manner.

A control method of the compressor protection device of the present invention having the above structure will be described below with reference to FIG.

The system control means 40a of the air conditioner adopted in the present invention is initialized in step S1 and then proceeds to step S2 to determine whether or not operation is being performed. When it is determined in step S2 that the air conditioner is operating, the process proceeds to step S3 to determine whether it is the heating operation. If it is the heating operation, the process proceeds to step S4 and the temperature sensing means 40. It is determined whether or not the outside air temperature detected in is a cold temperature.

The discriminating operation in step S4 is for determining whether or not the auxiliary accumulator 20 used in the present invention can be operated.

That is, when the outside air temperature is a cold temperature, the process proceeds to step S5 and the two-way valve 25 which is turned on so that the refrigerant directly flows into the accumulator 10.
The two-way valve driving means 40b is controlled so that the refrigerant is turned off, and the refrigerant is stored in the accumulator 10 and auxiliary accumulator 20
To flow into. Therefore, the liquid-state refrigerant generated by the two-layer separation phenomenon caused by the cold temperature is doubly filtered by the auxiliary accumulator 20 and the accumulator 10, and the liquid refrigerant circulated to the compressor 50 is completely removed. When the liquid refrigerant is completely removed in this way, a constant amount of oil is continuously supplied to the compressor 50.
In step S7, the heating operation can be performed in the optimum state.

When it is determined in step S4 that the outside air temperature is not the cold temperature, the process proceeds to step S6, and the two-way valve for circulating the refrigerant according to the normal refrigerant cycle as shown in FIG. After keeping 25 on, heating operation is performed in step S7.

On the other hand, if it is determined in step S3 that the heating operation is not performed, the process proceeds to step S8 to determine whether the operation of the air conditioner is the cooling operation,
In the case of cooling operation, the process proceeds to step S9 and the two-way valve 2
After keeping 5 on, the cooling operation is performed in step S10.

If it is determined in step S8 that the operation is not the cooling operation, the process proceeds to step S11 to determine whether the operation is the dehumidification operation. If it is determined in step S11 that the operation is not dehumidifying, the process returns to step S2 and the above steps are sequentially repeated. On the other hand, step S1
If the dehumidifying operation is determined in step 1, step S
After shifting to 12 and holding the two-way valve 25 in the ON state, the dehumidifying operation is performed in step S13.

[0024]

As described above, according to the compressor protection device and the protection method for an air conditioner according to the present invention, when the outside air temperature sensed by the temperature sensing means mounted on the body of the accumulator is cold. In this case, since the two-way valve is operated to completely filter the liquid-state refrigerant by the auxiliary accumulator and the accumulator and then flow into the compressor, the cooling / heating efficiency can be optimized. Further, since the obstacle to the oil return function to the compressor due to the liquid refrigerant is completely removed, it is possible to prevent the compressor from being worn and extend the life of the compressor.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a refrigerant flow in an air conditioner according to the present invention.

FIG. 2 is a circuit diagram of an important part of FIG.

FIG. 3 is a partial circuit diagram showing another embodiment of the present invention.

FIG. 4 is a flowchart showing a method of protecting a compressor according to the present invention.

FIG. 5 is a circuit diagram showing a flow of refrigerant in a conventional air conditioner.

[Explanation of symbols]

 10 Accumulator 20 Auxiliary accumulator 25 Two-way valve 30 Four-way valve 40 Temperature sensing means 40a System control means 40b Two-way valve drive means 50 Compressor 60 Indoor heat exchanger 70 Expansion device 80 Outdoor heat exchanger

Claims (6)

[Claims] 1. In an air conditioner having a heating system, a temperature sensing means mounted at a predetermined position of the air conditioner to sense an outside air temperature, and a two-way valve based on data output from the temperature sensing means. An air conditioner comprising a system control means for controlling the driving means and peripheral devices, and an auxiliary accumulator for activating the two-way valve to filter the liquid refrigerant passing through the accumulator and flowing into the compressor. Compressor protection device. 2. The two-way valve drive means is connected to a system control means for comparing the data output from the temperature sensing means for sensing the outside air temperature with reference data, and based on the comparison result from the system control means. The compressor protection device according to claim 1, wherein the operation of the two-way valve is controlled. 3. The two-way valve is turned off by a control signal output from the temperature sensing means and is connected to an inlet and an outlet of the auxiliary accumulator so that the refrigerant passes through the auxiliary accumulator. 2. The compressor protection device described in 2. 4. An auxiliary accumulator through which the flow of the refrigerant passes or is blocked according to the operation of the two-way valve is provided between the four-way valve and the accumulator.
The compressor protection device described in 1. 5. An auxiliary accumulator through which the flow of refrigerant passes or is blocked according to the operation of the two-way valve is provided between the accumulator and the compressor.
The compressor protection device described in 1. 6. A method of protecting a compressor of an air conditioner having a heating system, comprising a heating operation determining step of determining whether the operation of the air conditioner is a heating operation, and a heating operation in the heating operation determining step. If it is determined that the outside temperature is the cold temperature, the outside temperature is judged to be the cold temperature in the cold temperature judging step of sensing the outside air temperature to judge whether it is the cold temperature (-10 ° C. or less), and the cold temperature judging step. And a refrigerant flow control step of controlling the flow of the refrigerant so that the refrigerant passes through the auxiliary accumulator and the accumulator and flows into the compressor.