KR20080024378A - An air conditioner - Google Patents

Abstract

An air conditioner is provided to improve heating capability by compensating a degree of superheat and a suction pressure of refrigerant, and prevent deterioration of heating capability when the temperature of outdoor air falls rapidly. An air conditioner includes a plurality of compressors(32), an outdoor heat exchanger(38), discharge pipes connected with discharging sides of the compressors, a pipe connected with a discharging side of the outdoor heat exchanger in case of heating, and a plurality of bypass pipes(48) connecting a part of the discharging pipes with the pipe of the discharging side of the outdoor heat exchanger and guiding a part of refrigerant discharged from the compressors to the pipe of the discharging side of the outdoor heat exchanger.

Description

Air Conditioner {An Air Conditioner}

1 is a schematic diagram of a conventional air conditioner.

2 is a schematic diagram of a case in which the air conditioner of the present invention performs heating.

3 is a schematic view of the air conditioner of the present invention to perform the cooling action.

4 is a schematic diagram showing another embodiment of the present invention.

Figure 5 is a graph showing the difference between the refrigerant pressure of the present invention and the prior art.

Figure 6 is a graph showing the difference between the degree of superheat of the present invention and the prior art.

* Description of symbols on the main parts of the drawings *

32: compressor 35: first discharge branch pipe

36: second discharge branch pipe 37: discharge confluence pipe

38: outdoor heat exchanger 48, 49: bypass pipe

The present invention relates to an air conditioner, and more particularly, to an air conditioner used for both heating and cooling, and an air conditioner capable of increasing heating efficiency even when the outdoor temperature is low during heating.

As shown in FIG. 1, a conventional air conditioner is divided into an indoor unit 3 and an outdoor unit 1, and again, the indoor unit 3 includes an indoor heat exchanger 5 and an indoor blowing fan 7. 1) the compressor (9) for compressing the refrigerant, the outdoor heat exchanger (12) and the outdoor blower fan (15) for sucking and exhausting the external air toward the outdoor heat exchanger (12), the expansion valve and piping for expanding the refrigerant It consists of a flow path switching valve 18 of the four-way valve type which can switch the flowing refrigerant flow path.

On the discharge side of the compressor 9, a non-return valve 21 is provided so that the discharged refrigerant does not flow back to the discharge port side of the compressor 9 again.

When the air conditioner having such a configuration operates as a heat pump for heating, the refrigerant is compressed to a high temperature and high pressure state in the compressor (9) and moved to the indoor heat exchanger (5) along the pipe to undergo a condensation process. , The refrigerant in the condensation process transfers heat to the room by heat exchange with the relatively cold indoor air in the indoor heat exchanger (5).

Then, the refrigerant undergoing condensation is decompressed and expanded in the expansion valve to decrease its temperature and pressure. After that, the refrigerant undergoes evaporation while undergoing heat exchange with outdoor air in an outdoor heat exchanger (12), It is sucked back into the compressor (9).

In the case of operating the heat pump as described above, the refrigerant passing through the outdoor heat exchanger 12 is in a state where the temperature is considerably lowered, so even though it is cold air in winter, the heat is exchanged to absorb heat from the air to evaporate the process. Will go through.

However, when the outside air is very low, the temperature of the refrigerant passing through the outdoor heat exchanger 12 is not large, and thus the heat exchange efficiency is lowered. Accordingly, the refrigerant is difficult to evaporate. The refrigerant sucked into (9) becomes a liquid phase, which may cause failure of the compressor (9), and there is a problem that the suction pressure of the refrigerant entering the compressor (9) is also lowered. .

In addition, in that state, there was also a problem in that an additional refrigerant heating process such as an increase in superheat degree than usual is required to evaporate the refrigerant.

The present invention is to solve such a problem, it is an object to provide an air conditioner that can increase the superheat degree and the suction pressure of the refrigerant.

In particular, when the air conditioner combined with a heating and cooling system acts as a heat pump, even if the outdoor air temperature drops below a certain level, the suction pressure of the refrigerant can be increased and the superheat can be maintained at a constant level, thereby improving heating efficiency. To provide an air conditioner.

The present invention for achieving this object is a compressor; An outdoor heat exchanger; And a bypass tube connecting the discharge side of the compressor and the discharge side of the outdoor heat exchanger during heating.

The compressor may be provided in plural numbers, and the plurality of compressors may be provided with discharge pipes through which refrigerant is discharged, and the bypass pipe may be connected to the discharge pipes.

The discharge pipe may include a discharge branch pipe provided in each of the plurality of compressors, and a discharge conduit pipe to which the discharge branch pipes are joined, and the bypass pipe may be connected to a part of the discharge branch pipe. do.

In addition, the bypass pipe is characterized in that connected to the discharge confluence pipe.

In addition, the discharge branch pipe is provided with a non-return valve for preventing the back flow of the refrigerant, the bypass pipe is characterized in that connected to the outlet side of the non-return valve.

In addition, the air conditioner is characterized in that the combined heating and cooling.

The present invention also provides a plurality of compressors; An outdoor heat exchanger; Discharge pipes respectively connected to the discharge sides of the plurality of compressors; A pipe connected to the discharge side of the outdoor heat exchanger during heating; And a bypass pipe connecting part of the discharge pipe to the discharge side pipe of the outdoor heat exchanger during heating and guiding a part of the refrigerant discharged from the compressor to the discharge side pipe of the outdoor heat exchanger during heating. Provide an air conditioner.

In addition, the bypass tube is characterized in that a plurality provided.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 2, the present invention relates to a combined air conditioning and air conditioner, which is divided into an outdoor unit 30 and an indoor unit 50, and the outdoor unit 30 includes a plurality of compressors 32 for compressing a refrigerant; And a non-return valve 34 provided on the discharge side of the compressor 32 to prevent the reverse flow of the discharged refrigerant.

For convenience, in the present invention, a plurality of compressors will be classified into a first compressor 32a and a second compressor 32b, where the first and second discharge branch pipes 35 and 36 correspond to the number of compressors 32, respectively. The number of the compressor 32 and the discharge branch pipes 35 and 36 can be changed depending on the cooling and heating capacity or the surrounding conditions.

Here, the first and second discharge branch pipes 35 and 36 are connected to one discharge confluence pipe 37 to allow the refrigerant discharged from the plurality of compressors 32 to join the one pipe.

The outdoor unit 30 includes an outdoor heat exchanger 38 in addition to the compressor 32, an outdoor blower fan 40 that sucks outdoor air through the outdoor heat exchanger 38, and an expansion valve for decompressing and expanding the refrigerant. (42), and a flow path switching valve for switching the flow of the refrigerant to allow the air conditioner to perform cooling or heating.

The indoor unit 50 includes an indoor heat exchanger 52 and an indoor blower fan 54 that sucks and discharges indoor air with the indoor heat exchanger 52. Components and components inside the outdoor unit 30 are connected by a pipe.

Meanwhile, a separate bypass pipe 48 is connected to the first discharge branch pipe 35, and the bypass pipe 48 is connected to a pipe connected to the outdoor heat exchanger, and the bypass pipe 48 is connected to the first discharge branch pipe 35. The connection point is preferably a point A of the first discharge branch pipe 35 and a point B of the pipe connected to the outdoor heat exchanger 38, which is an air conditioner of the present invention operated by a heat pump to provide heating. This is to increase the superheat, pressure and suction amount of the refrigerant sucked into the compressor 32 by mixing with the low temperature low pressure refrigerant discharged from the outdoor heat exchanger 38 in the first compressor (32a).

3 shows a case in which the air conditioner of the present invention performs the cooling operation, wherein the bypass pipe 48 is branched at the point A of the first discharge branch pipe 35 to inhale the refrigerant of the outdoor heat exchanger 38. It is connected to point B on the side.

However, in this case, since the temperatures and pressures of the refrigerants at the points A and B are almost the same, the refrigerant rarely flows through the bypass pipe 48, and the refrigerant moves through the bypass pipe 48. Even if is mixed, there is no problem due to mixing because the state of the refrigerant passing through the two points are the same (state).

Meanwhile, the reason why the bypass pipe 48 of the present invention should be placed in the above-described position will be described with reference to FIGS. 2 and 3.

As shown in Figure 2, when the air conditioner of the present invention acts as a heat pump to heat the room, the outdoor heat exchanger 38, the evaporation process occurs.

However, when the bypass pipe 48 is connected to the inflow side (branch C) rather than the discharge side (branch B) of the outdoor heat exchanger 38, the bypass pipe 48 is discharged from the first compressor 32a to bypass the bypass. The high temperature and high pressure refrigerant passing through the pipe 48 is mixed with the refrigerant passing through the expansion valve 42.

Therefore, due to this mixing phenomenon, the pressure and temperature of the refrigerant rises before the outdoor heat exchanger 38 is introduced, and accordingly, the average temperature difference between the refrigerant passing through the outdoor heat exchanger 38 and the outdoor air decreases. The heat transfer from the air to the refrigerant causes a decrease, which means a decrease in the heating capacity, so the bypass pipe 48 should not be connected to the point C.

On the other hand, assuming that the bypass pipe 48 is connected to the suction side or the discharge side of the indoor heat exchanger 52, it is connected to the suction side of the indoor heat exchanger 52 is almost the temperature and pressure of the refrigerant It is technically meaningless because it is the same.

In addition, it is connected to the discharge side of the indoor heat exchanger 52 is to inject a refrigerant in a gaseous state of high temperature and high pressure into the refrigerant condensed in the indoor heat exchanger 52 and the temperature and pressure is changed to a liquid phase to the expansion valve ( 42) reduces the expansion effect under reduced pressure, generates noise during the expansion process, and at the same time, the supercooling degree of the refrigerant falls, resulting in lowering the overall heating efficiency.

Therefore, the bypass pipe 48 should be connected to the discharge side (point B) of the outdoor heat exchanger 38.

On the other hand, it is preferable that the point A where the first discharge branch pipe 35 and the bypass pipe 48 are connected to be provided at the outlet side of the first non-return valve 34a. This is to prevent the reverse flow to the first compressor (32a).

On the other hand, when the air conditioner of the present invention as shown in Figure 3 the indoor cooling action, the outdoor heat exchanger 38 serves as a condenser, the indoor heat exchanger serves as the evaporator 52.

However, since the refrigerant passing through the refrigerant discharge side (C portion) of the outdoor heat exchanger 38 has already undergone condensation in the outdoor heat exchanger 38, the refrigerant is decompressed to a certain degree than the state discharged from the compressor. .

In this state, when the bypass pipe 48 is connected to the C portion, the bypass pipe 48 is connected to the discharge side of the indoor heat exchanger 52 during the heating operation. The high-temperature, high-pressure gaseous refrigerant discharged immediately from the compressor 32a flows into the discharge side (point C) of the outdoor heat exchanger 38 through the bypass pipe 48 due to the pressure difference, thereby condensing the refrigerant. The temperature and pressure of the gas rises to disturb the supercooled state of the refrigerant, resulting in a non-condensed gas state.

In addition, when the refrigerant in the gaseous state is mixed with the refrigerant in the liquid state, noise is generated during the decompression expansion process in the expansion valve 42, and the expansion efficiency is reduced, which causes a reduction in the cooling efficiency.

The bypass pipe 48 does not play a large role in the cooling operation, but due to the above reasons, the A portion of the first discharge branch pipe 35 and the suction side B portion of the outdoor heat exchanger 38 are provided. Should be connected to

On the other hand, Figure 4 is another bypass pipe 49 is provided in addition to the bypass pipe 48 is connected to the first discharge branch pipe 35 in the air conditioner acts as a heat pump, the first, It is shown that the branched pipes 35 and 36 branch from a portion (part D) of the discharge confluence pipe 37 joined into one and are also connected to an E portion of a pipe connected to the outdoor heat exchanger 38.

The reason why the plurality of bypass pipes 48 and 49 are provided is that the low temperature low pressure refrigerant discharged from the outdoor heat exchanger 38 is mixed with the high temperature high pressure refrigerant discharged from the compressor 32 several times. It is to further increase the heating efficiency by further increasing the superheat, the suction pressure, and the amount of the refrigerant when flowing into the compressor 32.

Hereinafter, an operation of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 2, when the air conditioner of the present invention operates as a heat pump, the indoor heat exchanger 52 of the indoor unit after the refrigerant is compressed into a refrigerant having a high temperature and high pressure by the compressor 32. Go to).

Then, in the indoor heat exchanger 52, the indoor cold air introduced by the operation of the indoor blower fan 54 and the high temperature refrigerant exchange heat to supply high temperature air to the room.

Subsequently, the refrigerant having reduced temperature and pressure by dissipating heat into the room is expanded under reduced pressure while passing through the expansion valve 42 to lower the temperature and pressure, and flows into the outdoor heat exchanger 38 in that state.

The refrigerant introduced into the outdoor heat exchanger (38) exchanges heat with the outdoor air introduced by the outdoor blower fan (40). Here, since the temperature of the refrigerant is lower than the temperature of the outdoor air, the refrigerant removes heat from the outdoor air. The air is absorbed and evaporated, and the heat is deprived of the air by the outdoor blower fan 40.

In addition, the refrigerant discharged to the outdoor heat exchanger 38 in the evaporated state is mixed with the high temperature and high pressure refrigerant guided by the bypass pipe 48, and at this point, the superheat and pressure are increased. will be.

In particular, when the temperature of the outdoor air drops sharply and the difference between the refrigerant temperature passing through the outdoor heat exchanger 38 is narrowed, the heat exchange efficiency between the refrigerant and the outdoor air decreases relatively, so that the refrigerant does not evaporate smoothly. Accordingly, the superheat and the suction pressure of the refrigerant discharged from the outdoor heat exchanger 38 are reduced.

However, at this time, when a part of the high temperature and high pressure refrigerant discharged from the first compressor 32a is introduced into the pipe on the discharge side of the outdoor heat exchanger 38 under the guidance of the bypass pipe 48, The superheat and pressure of the coolant increases, and the amount of the coolant increases, thereby changing physical properties of the coolant sucked into the compressor 32 to improve the overall heating efficiency.

And, as shown in Figure 4, when the plurality of bypass pipes (48, 49) are provided, it is possible to double the improvement effect of the above-described heating efficiency.

Meanwhile, as shown in FIG. 2, the air conditioner operates as a heat pump while the bypass pipe 48 is connected only to the first discharge branch pipe 35, but does not operate the first compressor 32a. In the case where only the second compressor 32b is operated, the refrigerant from the second compressor 32b does not go through the bypass pipe 48, but the indoor heat exchanger 52 and the expansion valve 42. Heating is sequentially performed through the outdoor heat exchanger (38).

In this way, when the partial operation of operating only a part of the plurality of compressors 32 operates, the indoor and outdoor heat exchangers 39 and 52 are compared with the relative capacity of the indoor and outdoor heat exchangers 38 and 52, that is, the operating capacity of the compressor 32. ) Will increase in capacity.

That is, when only the second compressor 32b is driven, the amount of refrigerant compressed and flowing by the second compressor 32b will be smaller than when the first and second compressors 32a and 32b are driven. In comparison, the heat exchange capacity of the indoor and outdoor heat exchangers 38 and 52 will be relatively large.

Therefore, when the air conditioner of the present invention operates as a heat pump, even though the difference between the temperature of the refrigerant passing through the outdoor heat exchanger 38 serving as the evaporator and the outdoor air temperature becomes smaller than usual, the outdoor heat exchange is performed. The amount of refrigerant passing through the group 38 is relatively less than when all the compressors 320 are operated, so that all of the refrigerant can be evaporated in the outdoor heat exchanger 38.

Therefore, at this time, even if the high-temperature, high-pressure refrigerant flowing through the bypass pipe 48 is not mixed, the superheat degree of the refrigerant can be maintained, so that there is no major problem in implementing the heating capability.

FIG. 5 is a graph showing a change in pressure of the refrigerant sucked into the compressor when the bypass pipe is installed and when it is not installed, and shows a change when only one bypass pipe is installed as shown in FIG.

The pressure of the refrigerant when there is no bypass tube is P1 and the pressure of refrigerant when there is a bypass tube is P2. When there is a bypass tube and the high temperature and high pressure refrigerant flows in, the pressure is the confluence point of the bypass tube. In this case, the increased pressure is expressed by ΔP.

6 shows a change in the coolant superheat degree, when comparing the coolant superheat degree T1 when there is no bypass pipe and the coolant superheat degree T2 when there is a bypass pipe, the same as the pressure change. The superheat is raised by ΔT at the bypass pipe confluence point.

As such, when the high temperature and high pressure refrigerant meets and mixes with the evaporated low temperature and low pressure refrigerant, the suction pressure, the amount of refrigerant, and the degree of superheat increase when the compressor is sucked into the compressor, which may occur when the outside air temperature decreases sharply when the heat pump operates. It is possible to prevent the deterioration of heating capacity.

In particular, when the temperature of the outdoor air is sharply lowered and the temperature difference between the temperature of the outdoor air and the refrigerant passing through the outdoor heat exchanger is relatively narrowed, it is possible to prevent a decrease in heating capacity due to the increase in the pressure and superheat of the refrigerant as described above. will be.

According to the present invention as described above it is possible to increase the heating capacity by compensating for the superheat degree and the suction pressure, in particular, the temperature difference between the outdoor air temperature and the refrigerant passing through the outdoor heat exchanger is relatively narrow because the temperature of the outdoor air is drastically lowered. When it is lost, it is possible to prevent a decrease in heating capacity due to the increase in pressure and superheat of the refrigerant as described above.

Claims (8)

A compressor; An outdoor heat exchanger; And a bypass pipe connecting the discharge side of the compressor and the discharge side of the outdoor heat exchanger during heating. The method of claim 1, The compressor is provided in plural, the plurality of compressor is provided with a discharge pipe for discharging the refrigerant, the bypass tube is characterized in that the air conditioner is connected to the discharge pipe. The method of claim 2, The discharge pipe may include a discharge branch pipe provided in each of the plurality of compressors, and a discharge conduit pipe to which the discharge branch pipes join, and the bypass pipe may be connected to a portion of the discharge branch pipe. group. The method of claim 3, And the bypass pipe is connected to the discharge confluence pipe. The method of claim 3, The discharge branch pipe is provided with a non-return valve for preventing the back flow of the refrigerant, the bypass pipe is characterized in that connected to the outlet side of the non-return valve. The method of claim 1, The air conditioner is characterized in that the air-conditioning combined use. A plurality of compressors; An outdoor heat exchanger; Discharge pipes respectively connected to the discharge sides of the plurality of compressors; A pipe connected to the discharge side of the outdoor heat exchanger during heating; And a bypass pipe connecting part of the discharge pipe to the discharge side pipe of the outdoor heat exchanger during heating and guiding a part of the refrigerant discharged from the compressor to the discharge side pipe of the outdoor heat exchanger during heating. Air conditioner. The method of claim 7, wherein The bypass tube is provided with a plurality of air conditioners.

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