KR20050120239A - A control apparatus of a air-conditioning's capacity - Google Patents

Abstract

An air conditioner cooling apparatus comprising at least two compressors, comprising: at least two or more compressors having different compression capacities, an evaporator and a condenser commonly connected to each compressor, and an accumulator individually connected to each compressor; Connection pipes connecting the accumulators, first pressure control means provided on the discharge side of each compressor to prevent backflow of refrigerant, and a lower discharge side of the first pressure control means of each compressor so as to eliminate the pressure difference. And a second pressure control means provided between the suction side of each accumulator, to prevent the inflow of refrigerant to each compressor, to equalize the pressure between the discharge pipe and the suction pipe, and to stop the compressor during operation switching of the compressor. It is characterized in that the operation by eliminating the pressure difference.

Description

A CONTROL APPARATUS OF A AIR-CONDITIONING'S CAPACITY}

The present invention relates to an air conditioner, and more particularly, to an air conditioner cooling device capable of shortening a standby time of an air conditioner through at least two compressors and first and second pressure control means.

Recently, the air conditioner is provided with a cooling device in which the cooling capacity is automatically controlled. The above-mentioned cooling device is a simple control type using one constant speed compressor, a variable control type using a variable compressor, and a complex control type using two or more constant speed compressors.

As shown in FIG. 1, a conventional air conditioner including a combined controlled air conditioner includes a first compressor 100a and a second compressor 100b, an oil separator 600 commonly connected to each compressor, and a condenser connected to an oil separator. 300, an expansion device 500 connected to the condenser, an evaporator 200 connected to the expansion device, and a first accumulator 400a and a second accumulator 400b, which are commonly connected to the evaporator and individually connected to each compressor, respectively to each accumulator. The first capillary 700a and the second capillary 700b are connected to each other.

According to the conventional combined control type air conditioner described above, each compressor may be operated alone or operated at the same time according to the change of the cooling load. Therefore, the conventional combined control air conditioning apparatus can adjust the cooling capacity relatively efficiently.

However, in the conventional combined control air conditioner, when the compressor is controlled according to the change of the cooling load, the compressor of the appropriate capacity must be operated again while the whole compressor is stopped, and the other stopped when one compressor is operated. The other compressor which is stopped due to the refrigerant pressure being applied to the discharge side of one compressor is not only disabled, but also the refrigerant pressure is directly applied to the compressor that is stopped, which may cause the failure of the compressor. In addition, in order to operate the stationary compressor, a predetermined time is required until the pressure between the discharge unit and the suction unit of the stationary compressor reaches an equilibrium.

In addition, due to the change in refrigeration load and the compression capacity of the compressor, the arrival time of the equilibrium pressure of the stopped compressor is different. Therefore, sufficient safety time should be considered when designing the actual device. Sometimes it stops.

Therefore, in the conventional combined control air conditioner, the refrigerant discharged from the operating compressor is directly sucked to the discharge side of the stationary compressor, which causes the failure of the compressor, and only one compressor that is operated at the same time operates according to the change in the refrigeration load. If both units need to be operated again, a problem arises in that the compressor is stopped and restarted. At this time, the temperature of the room is increased and the user feels uncomfortable, and after the temperature is increased, the power consumption increases, so it is not economical, and the energy efficiency obtained by varying the cooling capacity with a plurality of compressors cannot be obtained. .

Accordingly, the present invention is to solve the above-mentioned problems of the prior art, improve the efficiency of the device by improving the structure of the air conditioner air conditioner having at least two compressors, stop through the pressure balance control means such as solenoid valve The purpose of the present invention is to increase the energy efficiency and to keep the room comfortable by shortening the pressure equilibrium arrival time of the compressed compressor, that is, operating standby time.

In order to achieve the above object, the air conditioner cooling apparatus according to the present invention comprises at least two compressors having different compression capacities, at least two expansion devices connected to the condenser and a condenser connected in common with each compressor, and an evaporator connected to the expansion device, An accumulator connected separately between one evaporator and each compressor, a connecting pipe connecting the accumulators to recover oil, first pressure control means provided on the discharge side of each compressor to prevent the inflow of refrigerant, and the discharge side of each compressor. A second pressure control means is provided between the bottom discharge side of the first pressure control means of each compressor and the suction side of each accumulator so as to eliminate the pressure difference between the suction side and the suction side.

Hereinafter, an air conditioner cooling apparatus according to the present invention will be described in detail with reference to the drawings.

Figure 2 is a schematic diagram showing an embodiment of an air conditioner cooling apparatus according to the present invention.

As shown in FIG. 2, in the air conditioner cooling apparatus according to the present invention, the compressor is provided with at least two compressors 11a and 11b, and the first compressor 11a and the second compressor 11b have the same compression capacity. Preferably, they may have different compression capacities. The above-mentioned compressor compresses the gas of low temperature and low pressure into a gaseous refrigerant of high temperature and high pressure to form a refrigerant movement cycle through the condenser 50 and the evaporators 81a and 81b.

The first accumulator 14a is connected to the first compressor 11a and the evaporators 81a and 81b to recover the low-temperature low-pressure gas refrigerant and oil which have been phase-shifted through the evaporators 81a and 81b, and stores the excess refrigerant. . The second accumulator 14b is connected to the second compressor 11b and the evaporators 81a and 81b to recover the low-temperature low-pressure gas refrigerant and oil which have been phase-shifted through the evaporators 81a and 81b, and stores the excess refrigerant. .

In addition, the first pressure control means is to prevent the refrigerant from flowing into the compressor through the other compressor discharge pipe when the refrigerant of the high temperature and high pressure is discharged from each of the compressors (11a, 11b) to reduce the failure and operation efficiency of the compressor, It is provided between the condenser 50 and each of the first compressor 11a and the second compressor 11b in one direction, respectively, and the flow of the refrigerant is discharged from the compressors 11a and 11b by the above-described first pressure control means. Only in the direction.

At this time, the check valves 41a and 41b are preferable as the first pressure control means.

Further, the second pressure control means is provided between the lower discharge side of the first pressure control means of each compressor and the suction side of each accumulator so as to eliminate the pressure difference between the discharge side and the suction side of each compressor to shorten the operation waiting time. By relieving the pressure difference between the discharge side and the suction side of each compressor, it is possible to prevent the oil backflow and to smoothly operate each compressor and to shorten the standby time.

At this time, it is preferable that the above-mentioned second pressure control means is composed of solenoid valves 31a and 31b.

In addition, a connecting pipe 20 is connected between the first accumulator 14a and the second accumulator 14b, and through the branch pipes 6a and 6b together with the low temperature low pressure refrigerant passing through the evaporators 81a and 81b. The oil recovered to each accumulator (14a, 14b) is to be appropriately distributed according to the capacity of each compressor to maintain the oil level of each accumulator through the flow of oil.

Hereinafter, with reference to FIG. 2, operation | movement of the air conditioner cooling apparatus comprised as mentioned above is demonstrated.

First, when the air conditioner air conditioner according to the present invention is described along with the flow of the refrigerant, the low-temperature low-pressure gaseous refrigerant is compressed into a high-temperature high-pressure gaseous refrigerant by at least two compressors (11a, 11b), the high-temperature high-pressure gas The state refrigerant is discharged through the discharge pipes 4a and 4b. At this time, the reverse flow of the refrigerant into the compressor stopped by the first pressure control means provided in the discharge pipe is prevented, and the high temperature and high pressure passing through each discharge pipe is prevented. The gaseous refrigerant is introduced into the condenser 50 through the connecting pipe 5, and the refrigerant introduced into the condenser is condensed and converted into a liquid refrigerant having a low temperature and high pressure, and then expanded in the expansion devices 61a and 61b to obtain a low temperature and low pressure. It becomes an abnormal state coolant, and is subsequently transferred to the evaporators 81a and 81b to change into a gaseous state of low temperature and low pressure, taking heat from the surroundings, and cooling the air around the evaporator. At this time, the refrigerant flows into the evaporator connected through the connector 91 by the service valves 71a and 71b according to the room temperature. The refrigerant which cooled the ambient air in the evaporator is each accumulator which is an oil separation and surplus refrigerant accumulating means through a connecting pipe 5 provided on one side of the evaporator and branch pipes 6a and 6b branched at the ends of the connecting pipe 5. 14a, 14b), and when only one compressor is operated, the excess oil introduced into the accumulator of the stationary compressor is sucked into the accumulator of the compressor in operation through the connecting pipe 20 connecting the accumulators, Oil and refrigerant flow into each compressor connected to each accumulator to form a cycle of recondensation.

Looking at how the cooling device according to the invention is operated according to the cooling load change;

First, in the case of simultaneously operating each compressor due to the change in cooling load, the first and second solenoid valves 31a and 31b, which are the second pressure control means, are energized and opened, and the pressure is balanced accordingly. Close the solenoid valves and start each compressor. At this time, the high-temperature, high-pressure gaseous refrigerant compressed by the compressors 11a and 11b is discharged into the discharge pipes 4a and 4b, and then each check valve is a first pressure control means configured in one direction to prevent the inflow of the refrigerant. The condenser 50 is introduced into the condenser 50 through the connecting pipe 5 by 41a and 41b, and is condensed in the condenser 50 and phase-converted to a liquid refrigerant, and then the expansion devices 61a and 61b connected to the condenser 50. Through the evaporators 81a and 81b connected to the connector 91, respectively, or through the evaporators 81a and 81b respectively, the refrigerant is phase-shifted to the gaseous refrigerant or each of the branch pipes 6a and 6b is maintained. Through each accumulator 14a, 14b is introduced.

In addition, the gaseous and liquid refrigerants introduced into the accumulators 14a and 14b and the oil discharged along with the refrigerant from the compressors are distributed according to the refrigerant flow rate, and the oil level of each accumulator is adjusted through the flow of oil. The oil which has been excessively introduced to remain the same is recovered through the connecting pipe 20 and flowed into the respective compressors 11a and 11b through the accumulators 14a and 14b. And this cycle is performed repeatedly.

Second, when only the first compressor 11a is operated, power is applied to the first solenoid valve 31a, which is the second pressure control means, and the second solenoid valve 31b, which is the second control means, to open the pressure balance. After closing the first solenoid valve 31a, only the first compressor 11a is operated. The refrigerant discharged from the first compressor (11a) described above is blocked by the check valve (41b), which is the first pressure control means, and is not applied to the stationary second compressor (11b) side through the branch pipe (6b). The oil flowing into the second accumulator 14b of the stationary second compressor 11b flows through the connecting pipe 20 to the first accumulator 14a of the first compressor 11a that is in operation, so that the oil is biased. The second compressor (11b) which is stopped and keeps running at any time.

In addition, even when the 2nd compressor 11b is operating and the 1st compressor 11a is stopped, the 1st compressor 11a which is always stopped can be operated similarly.

Third, when the cooling load decreases while the compressors 11a and 11b are all operated and the first compressor 11a is stopped, the cooling load increases again and the stopped first compressor 11a is to be restarted. In the first case, when the first compressor 11a and the second compressor 11b are operated simultaneously, the discharge pipe 4a between the discharge side of the first compressor 11a and the check valve 41a serving as the first pressure control means and The inside of the first compressor 11a is at a high pressure. At this time, when the first compressor 11a is stopped, the high pressure side refrigerant of the second compressor 11b is blocked from entering the first compressor 11a by the check valve 41a which is the first pressure control means. However, the high pressure already generated by the first compressor 11a may not be removed, and the oil of the first compressor 11a may be removed due to the pressure difference between the discharge side and the suction side of the first compressor 11a. The phenomenon of backflow to the accumulator 14a occurs. At this time, since the refrigerant pressure is applied to the discharge side of the first compressor 11a, the first compressor 11a must be restarted after a constant refrigerant exhaust time. As such, when switching of the compressor is required, in particular, the first compressor 11a and the second compressor 11b are operated at the same time, and either the first or the second compressor is stopped, and then the first or the second compressor is restarted. When one operation is required, an operation waiting time is required to solve the pressure difference described above for operation of either the first or second compressor. The above described standby time can be eliminated through the solenoid valves 31a and 31b which are the second pressure control means according to the present invention. The above-mentioned solenoid valves 31a and 31b, which are the second pressure control means, eliminate the pressure difference between the discharge side and the suction side of the compressor and achieve a uniform pressure, so that the first compressor 11a immediately even during operation of the second compressor 11b without waiting time. ) Can be operated.

For example, in the case where the first compressor 11a and the second compressor 11b are operated at the same time and then both are stopped and only the first compressor 11a is operated alone, the suction side pressure after stopping is approximately 8 kg / cm2g. When only the first compressor 11a is operated alone, the first and second suction side pressures drop from approximately 8 kg / cm 2 g to 4 kg / cm 2 g. At this time, the oil of the second compressor (11b) is flowed back to the second accumulator (14b) due to the pressure difference and the reversed oil is moved to the first compressor (11a) in operation through the connecting pipe 20, the second compressor The performance degradation of (11b) occurs. Therefore, when only the first compressor 11a is operated, the solenoid valve 31b of the second compressor 11b must be operated in an open state.

In the above description, the technical idea of the air conditioner air conditioner having at least two compressors and the first and second pressure control means is described together with the accompanying drawings. It is not intended to limit.

In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

As described above, when the air conditioner air conditioner according to the present invention is used, the inflow of refrigerant and oil of each compressor is prevented and the discharge side of each compressor is controlled through a control means such as a solenoid valve when switching of the compressor is required. Since the pressure balance between the suction side and the suction side can be achieved, power consumption can be reduced and energy efficiency can be obtained by operating standby time. In addition, there is an effect that can always maintain the comfort of the room.

1 is a schematic view of a cooling capacity adjusting device equipped with two compressors according to the prior art.

Figure 2 is a schematic diagram of the air conditioning capacity adjusting apparatus of the present invention.

 [Explanation of symbols on the main parts of the drawings]

4a, 4b: discharge tube 5: connector

6a, 6b: branch pipe 11a: first compressor

11b: second compressor 14a: first accumulator

14b: 2nd accumulator 20: connection piping

31a, 31b: solenoid valve 41a, 41b: check valve

50: condenser 61a, 61b: expansion device

71a, 71b: service valve 81a, 81b: evaporator

91: connector

Claims (7)

Air conditioning cooling with at least two compressors, a condenser connected in common with the discharge tube of each compressor, at least two expansion devices connected to the condenser, an evaporator connected respectively to the expansion device, and an accumulator individually connected between the evaporator and each compressor In the apparatus, And a second pressure control means between the discharge pipe of each compressor and the suction side pipe of each accumulator so as to prevent the pressure balance between the discharge side and the suction side of the compressor and the reverse flow of oil. The method of claim 1, Air conditioner cooling device further comprises a connection pipe 20 provided between the accumulator to maintain the oil level of each accumulator through the flow of oil. The method of claim 1, And a first pressure control means between the discharge pipes (4a, 4b) and the condenser (50) of each compressor to prevent backflow of the refrigerant. The method of claim 2, The first pressure control means is an air conditioner cooling device, characterized in that consisting of check valve (41a, 41b). The method of claim 1, And the second pressure control means is a solenoid valve (31a, 31b). The method of claim 1, Each compressor has a different compression capacity of the air conditioner cooling apparatus. At least two compressors 11a and 11b having different compression capacities; A condenser 50 connected in common with the discharge pipes of the respective compressors; At least two expansion devices (61a, 61b) connected to the condenser; At least two evaporators 81a and 81b respectively connected to the expansion device; Accumulators (14a, 14b) individually connected between each evaporator and each compressor to recover oil discharged with refrigerant from each compressor and to store excess refrigerant; Check valves (41a, 41b) respectively provided between the discharge pipe and the condenser of the respective compressor to prevent the reverse flow of the refrigerant; Solenoid valves 31a and 31b respectively provided between the discharge pipe of each compressor and the suction pipe of each accumulator to prevent pressure equalization between the discharge side and the suction side of the compressor and backflow of oil; And Air conditioner cooling device comprising a connecting pipe 20 provided between the accumulator to maintain the oil level of each accumulator through the flow of oil.