KR101513305B1 - Injection type heat pump air-conditioner and the converting method for injection mode thereof - Google Patents

Abstract

The present invention relates to an injection mode air conditioner and a method for switching an injection mode of the air conditioner, the apparatus including a compressor, an indoor heat exchanger, an outdoor heat exchanger, and a main expansion valve, An injection pipe for supplying gaseous refrigerant in a receiver provided between the valves to an injection port formed in the compressor, and a bypass pipe for selectively introducing at least a part of the refrigerant discharged from the discharge port of the compressor into the suction port of the compressor .

According to the injection mode switching method for an air conditioner having both an air-cooling and heating type air conditioner and an air conditioner according to the present invention, it is possible to prevent a sudden decrease in the pressure on the suction port side of the compressor at the initial stage of the injection mode of the air conditioner, There is an effect that it is possible to prevent the occurrence of the problem.

Air conditioner, injection, bypass piping

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mode switching type air conditioner and an air conditioner,

The present invention relates to an air-conditioner and an air-conditioner, which prevents a sudden decrease in pressure of a suction port of a compressor at the initial stage of an injection mode during operation of the air conditioner and allows the progress of the injection mode to proceed more stably, The present invention relates to a method of switching an injection mode of an air conditioner.

Generally, a heat pump air conditioner reversibly uses a transport mechanism for heat transferred to a refrigeration cycle consisting of compression-condensation-decompression-evaporation of a refrigerant to combine cooling and heating.

1 is a configuration diagram showing a conventional heat pump air conditioner.

As shown in the figure, the conventional heat pump air conditioner for combined cooling and heating operation includes a compressor 10, an indoor heat exchanger 20, an indoor heat exchanger 21, an outdoor heat exchanger 30, an outdoor heat exchanger 30, A main expansion valve 40, a four-way valve 50, and an accumulator 110.

The compressor 10 has a suction port 11 and a discharge port 12 and compresses the low temperature low pressure gaseous refrigerant sucked from the suction port 11 and discharges it through the discharge port 12 in a high temperature and high pressure gas state.

The four-way valve 50 connects the discharge port 12 of the compressor 10 to the outdoor heat exchanger 30 and the indoor heat exchanger 20 according to the user's selection, And the flow of the refrigerant is switched according to the heating operation mode.

Meanwhile, the indoor heat exchanger (20) functions as an evaporator which is located indoors, evaporates the refrigerant in the low-temperature and low-pressure liquid state to the gaseous state in the cooling operation mode, and the refrigerant in the high- And functions as a condenser for condensing the refrigerant into a high-pressure liquid state at a normal temperature, and performs heat exchange with ambient air in response to a change in enthalpy of the refrigerant.

The indoor air blowing fan 21 is disposed on the side of the indoor heat exchanger 20 to promote the heat exchange function of the indoor heat exchanger 20 as an evaporator or a condenser and to generate cold air or warm air necessary for the room .

The main expansion valve 40 is connected between the indoor side heat exchanger 20 and the outdoor side heat exchanger 30 so as to reduce the pressure of the liquid refrigerant at room temperature and high pressure, And is preferably applied to a valve whose degree of opening is controlled electronically.

The outdoor heat exchanger (30) is provided on the outdoor side opposite to the indoor heat exchanger (20), and functions as a condenser during cooling operation and a heat exchanger with ambient air as an evaporator during heating operation.

The outdoor air blowing fan 31 is installed on the side of the outdoor heat exchanger 30 and is operated so as to promote the heat exchange (as a condenser or an evaporator) of the outdoor heat exchanger 30.

Meanwhile, the accumulator 110 functions to filter the refrigerant remaining in the liquid state without phase change in the refrigerant flowing into the compressor 10 from the four-way valve 50 and to supply the oil to the compressor 10 side.

On the other hand, the cooling operation and the heating operation mode of the air conditioner are changed to the switching of the four-way valve 50 according to the user's selection, and the flow of the refrigerant is changed at that time.

In recent years, an injection method of a compressor has been introduced to improve the cooling or heating capability of the conventional heat pump air conditioner. As shown in FIG. 1, the indoor heat exchanger And a sub capillary tube 60 and a receiver 70. The sub capillary tube 60 is connected to the main expansion valve 40 via a capillary tube.

In the heat pump air conditioner of this injection type, the liquid refrigerant contained in the receiver (70) among the refrigerants that have passed through the indoor heat exchanger (20) during the heating operation is passed through the outdoor expansion valve (40) (30), and the gaseous refrigerant contained in the receiver (70) is injected into the injection port (13) of the compressor (10).

Therefore, it becomes possible to increase the amount of circulation of the refrigerant circulating in the air conditioner cycle, thereby improving the heating capacity of the air conditioner.

However, in the conventional injection mode, as the pressure at the compressor suction port decreases rapidly, the compression ratio of the compressor, that is, the refrigerant pressure ratio on the compressor suction side with respect to the refrigerant pressure on the compressor discharge port side, instantaneously rises rather than the injection mode And the system malfunction of the air conditioner is caused thereby.

In addition, during the injection mode of the air conditioner, as the temperature of the indoor heat exchanger 20 is higher than the normal operation state, the cycle of the air conditioner becomes unstable, resulting in a malfunction of the system.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an air conditioner capable of preventing a pressure drop on a compressor intake port at the initial stage of an injection mode of the air conditioner and preventing a malfunction of the air conditioner system And a method for switching an injection mode of the air conditioner.

In order to achieve the above object, the present invention provides an air conditioner for a combined cooling and heating type, which includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, and a main expansion valve. The indoor heat exchanger and the main expansion valve And a bypass pipe for selectively introducing at least a portion of the refrigerant discharged from the discharge port of the compressor into the suction port of the compressor, characterized by further comprising: an injection pipe for supplying the gaseous refrigerant in the receiver, do.

The first and second solenoid valves are provided in the injection pipe and the bypass pipe, respectively, and the second solenoid valve is opened in the injection mode of the air conditioner in which the first solenoid valve is opened do.

According to another aspect of the present invention, there is provided a method of switching an injection mode of an air-conditioning unit of an air-cooling and heating type according to the present invention, the method comprising the steps of: (a) Determining an operation mode; (b) if the rapid heating mode is determined in step (a), completely opening the main expansion valve and opening the first and second solenoid valves; (c) wherein (b) after a predetermined time (t ₁₎ from the step has elapsed, the outdoor air and the outdoor determines the temperature difference of the heat exchanger, and the determination result, if the absolute value of the temperature difference between set temperature difference is less than said second solenoid Closing the valve; And (d) gradually reducing the opening degree of the main expansion valve after a lapse of a predetermined time (t ₂ ) from the step (c).

Further, the step (d) may further include increasing a rotational speed of the indoor ventilation fan.

In the step (c), when the absolute value of the temperature difference between the outdoor air and the outdoor heat exchanger exceeds the preset temperature difference, the step (c) is repeated a predetermined number of times.

According to the injection mode switching method of the air-conditioning unit and the air-conditioner of the present invention, it is possible to prevent the suction-side pressure of the compressor from dropping at the initial stage of the injection mode of the air conditioner, It is possible to prevent the occurrence of malfunctions of the apparatus.

In addition, if the temperature difference between the outdoor air and the outdoor heat exchanger exceeds the set temperature difference while the air conditioner is in the injection mode, the refrigerant passing through the bypass pipe and the accumulator continuously flows into the suction port side of the compressor to raise the temperature of the indoor heat exchanger It is possible to prevent an abnormal operation of the air conditioner due to an increase in the temperature of the indoor heat exchanger.

Further, when the injection mode is in progress, the opening degree of the main expansion valve is gradually decreased and the rotation speed of the ventilation fan in the indoor side is increased, whereby the temperature of the indoor heat exchanger, The system can be prevented from malfunctioning and the injection mode can be stably performed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration diagram illustrating an air conditioner according to an embodiment of the present invention.

2, the air-conditioning and air-conditioning type air conditioner according to the embodiment of the present invention includes a compressor 10, an indoor heat exchanger 20, an outdoor heat exchanger 30, a main expansion valve 40, And a four-way valve (50). The refrigerant is phase-changed while the refrigerant circulates through the components and a pipe connecting the components.

The compressor 10 compresses the low-temperature and low-pressure gaseous refrigerant sucked from the suction port 11 and discharges it through the discharge port 12 in a high-temperature, high-pressure gaseous state.

Further, the indoor-side and outdoor-side heat exchangers (20, 30) are connected to the compressor (10) by piping to perform heat exchange with outside air.

The main expansion valve 40 is connected between the indoor heat exchanger 20 and the outdoor heat exchanger 30 to decompress the high pressure liquid refrigerant to a low pressure liquid state.

2, a sub capillary tube 60 connected in series with the main expansion valve 40 is provided in a pipe between the indoor heat exchanger 20 and the outdoor heat exchanger 30 And a receiver 70 is provided between the main expansion valve 40 and the sub capillary tube 60 for separating the gaseous refrigerant and the liquid refrigerant.

A one-way valve (80) connected in parallel to the sub capillary tube (60), opened during the cooling operation of the air conditioner and closed during heating operation to form no flow path is connected to the indoor heat exchanger And the outdoor heat exchanger (30).

The four-way valve 50 connects the discharge port 12 of the compressor 10 to the indoor heat exchanger 20 or the outdoor heat exchanger 30 to change the flow path of the refrigerant during the cooling / .

That is, the refrigerant discharged through the discharge port of the compressor 10 during the cooling operation of the air conditioner passes through the outdoor heat exchanger 30, the main expansion valve 40, the one-way valve 80 and the indoor heat exchanger 20, And the like are sequentially circulated.

Conversely, when the air conditioner is in the heating operation, the refrigerant discharged through the discharge port of the compressor 10 flows into the outdoor heat exchanger 20, the sub capillary tube 60, the main expansion valve 40, (30), and the like.

Accordingly, the indoor heat exchanger 20 serves as an evaporator during the cooling operation of the air conditioner, and the indoor heat exchanger 20 serves as a condenser during the heating operation.

On the other hand, the indoor side air blowing fan 21 and the outdoor side air blowing fan 31 are provided on the side portions of the indoor side and outdoor side heat exchangers 20, 30, respectively, so as to increase heat exchange efficiency.

In addition, the air conditioner is provided with an air conditioner for measuring the temperature of each component of the air conditioner including the indoor and outdoor heat exchangers (20, 30), the temperature of the pipe connecting the components, A number of temperature sensors are mounted.

In addition, an injection pipe 90 is formed to supply the gaseous refrigerant in the receiver (70) to the injection port (13) formed in the compressor (10) to enable the injection mode operation of the air conditioner.

Here, the injection pipe 90 is for increasing the heating efficiency by increasing the circulation amount of the refrigerant circulating in the air conditioner cycle when the heating load during the heating operation of the air conditioner is larger than normal, Is gently introduced into the injection port (13) of the compressor (10) through the injection pipe (90) by a pressure difference relative to the compressor (10).

The injection pipe 90 may also be used for increasing the cooling efficiency during the cooling operation of the air conditioner.

In addition, in order to supply refrigerant from the four-way valve 50 to the suction port 11 of the compressor 10 and to filter the refrigerant remaining in the liquid state in the gas phase, (Not shown).

When the refrigerant flows into the compressor 10 through the injection pipe 90, the conventional air conditioner instantaneously detects the refrigerant flowing into the compressor 10 due to the increase in the refrigerant suction amount of the compressor 10, The pressure ratio between the suction port 11 of the compressor 10 and the discharge port 12 may rise sharply.

As a result, the load of the motor constituting the compressor 10 and the wear of the mechanical parts cause a reliability problem of the main parts. Further, in order to prevent this, the operation of the protective mode of the air conditioner or the temperature of the indoor heat exchanger There is a problem that malfunction of the air conditioner system due to sharp rise or the like occurs.

2, in the injection mode of the air conditioner, at least a part of the refrigerant discharged from the discharge port 12 of the compressor 10 is supplied to the accumulator 110 via the accumulator 110 And then flows into the suction port (11) of the compressor (10), thereby forming a bypass piping (100) for preventing the sudden rise of the pressure ratio described above.

That is, the air conditioner according to the embodiment of the present invention opens the bypass piping 100 at the initial stage of the injection mode to increase the refrigerant suction amount of the compressor 10, 10) can be prevented, and as a result, malfunction of the air conditioner system can be prevented.

The first and second solenoid valves 91 and 101 are provided in the injection pipe 90 and the bypass pipe 100 and the injection mode of the air conditioner due to the opening of the first solenoid valve 91 The second solenoid valve 101 is also opened.

At this time, the second solenoid valve 101 may be opened at the same time as the first solenoid valve 91, or may be opened with a time difference as necessary.

That is, whether or not the first and second solenoid valves 91 and 101 are open is determined by signal transmission from the control unit according to the selection of the air conditioner.

Hereinafter, a method of switching an injection mode of an air-conditioning type air conditioner according to an embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG.

3 is a block diagram showing the configuration of switching the injection mode of the air conditioner according to the embodiment of the present invention.

As shown in the figure, the controller 120 controls the temperature of the outdoor heat exchanger 30, the temperature of the outdoor air, and the temperature of the outdoor heat exchanger 30, And a temperature sensor 122, 123, and 124 for measuring the temperature of the room, respectively.

The control unit 120 determines the input signal and outputs the signal to the main expansion valve 40, the four-way valve 50, the one-way valve 80, and the first and second solenoid valves 91 and 101 And the like.

4 is a flowchart illustrating an injection mode switching method of an air conditioner according to an embodiment of the present invention.

First, when power is supplied to the air conditioner to operate the air conditioner (S10), the control unit 120 determines whether the operation mode of the air conditioner is the cooling mode or the heating mode (S20) Can be judged by using the signal of the signal processor 121.

2, the outdoor heat exchanger 30, the main expansion valve 40, the one-way valve 80 (see FIG. 2) And the indoor heat exchanger 20 are sequentially circulated in the cycle of the air conditioner.

On the other hand, when the judged operating mode is the heating mode, the refrigerant is supplied to the compressor 10, the indoor heat exchanger 20, the sub capillary tube 60, the main expansion valve 40 and the outdoor heat exchanger (30) in the order of the cycle of the air conditioner.

In the heating mode of the air conditioner, the air conditioner is provided with a normal heating mode for allowing normal heating operation. Also, the user's selection through the input unit 121 or the temperature measurement by the temperature sensors 123 and 124 A rapid heating mode in which the amount of circulation of the refrigerant is increased by the control signal of the control unit 120 when the temperature difference between the outside air and the room is equal to or more than a predetermined value.

When the step S20 is completed, the controller 120 determines whether the heating operation mode of the air conditioner is the normal heating mode or the rapid heating mode (S21).

If it is determined in step S21 that the operation mode of the air conditioner is rapid heating or injection mode, the controller 120 fully opens the main expansion valve 40, and the first and second solenoid valves 91 and 101 are opened (S30).

The gaseous refrigerant, which is accommodated in the receiver 70 and has a pressure higher than that of the suction port 11 of the compressor 10, is naturally introduced into the injection port 13 of the compressor 10 by the pressure difference .

A part of the refrigerant discharged to the discharge port 12 of the compressor 10 also flows into the suction port 11 side of the compressor 10 through the branched bypass piping 100.

Therefore, the air conditioner according to the embodiment of the present invention can prevent the pressure of the suction port 11 side of the compressor 10 from being reduced instantaneously while the injection pipe 90 is opened.

When the S30 step is completed, the control unit 120 determines whether or not the predetermined time (t ₁₎ has elapsed (S40).

When it is determined that the predetermined time (t ₁₎ has elapsed from the S40 step it is determined whether or not the controller 120, the temperature of outside air to help the outdoor heat exchanger than the absolute value of the temperature difference between a set temperature difference (ΔT _SET) of 30 ( S41).

On the other hand, if the case is not a certain time (t ₁₎ it has elapsed in step S40 the control unit 120 repeats the step S40.

As described above, as the refrigerant suction amount of the compressor 10 instantaneously increases due to the opening of the injection pipe 90, the cycle of the air conditioner in the injection mode early stage becomes unstable. ₁ ) means the set time until the cycle is stabilized after circulating the air conditioner cycle approximately two to three times after the injection mode is executed, which is a preset value obtained by the test.

If it is determined in step S41 that the absolute value of the temperature difference between the outdoor air and the outdoor heat exchanger 30 is equal to or smaller than the set temperature difference T _SET , the control unit 120 determines that the cycle of the air conditioner in the injection mode is in a stable state And outputs a control signal to close the second solenoid valve 101 (S42).

More specifically, when the absolute value of the temperature difference between the outside temperature and the outdoor heat exchanger 30 is equal to or lower than the set temperature difference? T _SET in step S41, when the second solenoid valve 101 is closed, the first solenoid valve 91 is opened The heat efficiency of the air conditioner is increased because the temperature of the indoor heat exchanger 20 is raised.

On the other hand, if the absolute value of the temperature difference between the outdoor air and the outdoor heat exchanger 30 exceeds the set temperature difference? T _SET in step S41, the controller 120 determines that the cycle of the air conditioner in the injection mode is unstable And maintains the open state of the second solenoid valve 101 (S43, S44).

At this time, the control unit 120 repeats the steps S40, S43, and S44 by a preset number of circulation C, and if the number of cycles of circulation of the refrigerant exceeds the preset number C, do.

When the S42 step is completed, the control unit 120 determines whether or not the predetermined time (t ₂₎ has passed (S50).

When it is determined that the predetermined time (t ₂₎ elapsed in the S50 step, the control unit 120, with for transmitting a control signal to the main expansion valve (40) opens the main expansion valve 40 so as to also gradually reduce the , And transmits a control signal to increase the rotational speed of the indoor side blowing fan 21 (S51).

Therefore, the amount of circulation of the refrigerant circulating in the air conditioner cycle is gradually reduced, and the heat exchange amount of the indoor heat exchanger 20 is increased.

On the other hand, in the step S51, the reduced blowing amount of the indoor side air blowing fan 21 is set to at least more than the weak wind condition, or at least the strong wind condition.

This makes it possible to prevent the abnormal operation of the air conditioner cycle due to the high temperature of the indoor heat exchanger (20) having a relatively high temperature condition as compared with the outdoor heat exchanger (30).

When the step S51 is completed, the control unit 120 determines again whether the operation mode of the air conditioner is the injection mode (S60).

If it is determined in step S60 that the injection mode is maintained, the control unit 120 determines whether the OFF signal of the air conditioner is input (S70). If the input mode is the input mode, Repeat step S51.

If it is determined in step S60 that the injection mode is not selected, step S20 is performed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein. Or modification.

1 is a configuration diagram showing a conventional air conditioner.

2 is a configuration diagram illustrating an air conditioner according to an embodiment of the present invention;

3 is a block diagram showing a configuration for switching an injection mode of an air conditioner according to an embodiment of the present invention;

4 is a flowchart illustrating a method of switching an injection mode of an air conditioner according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE SYMBOLS

10: compressor 11: inlet

12: Discharge port 13: Injection port

20: indoor heat exchanger 21: indoor air blowing fan

30: outdoor heat exchanger 31: outdoor air blowing fan

40: main expansion valve 50: four-way valve

60: sub capillary tube 70: receiver

80: One-way valve 90: Injection piping

91: first solenoid valve 100: bypass piping

101: Second solenoid valve 110: Accumulator

120: control unit 121: input unit

122: outdoor heat exchanger temperature sensor 123: outdoor temperature sensor

124: Room temperature sensor

Claims (5)

delete delete A compressor, an indoor heat exchanger, an outdoor heat exchanger, and a main expansion valve, An injection pipe for supplying gaseous refrigerant in a receiver provided between the indoor heat exchanger and the main expansion valve to an injection port formed in the compressor; And Further comprising a bypass pipe for selectively introducing at least a portion of the refrigerant discharged from the discharge port of the compressor into the suction port of the compressor, Wherein the first and second solenoid valves are provided in the injection pipe and the bypass pipe respectively and the second solenoid valve is opened in the injection mode of the air conditioner in which the first solenoid valve is opened, In the injection mode switching method of the harmonizer, (a) determining a heating operation mode of the air conditioner; (b) if the rapid heating mode is determined in step (a), completely opening the main expansion valve and opening the first and second solenoid valves; (c) wherein (b) after a predetermined time (t ₁₎ from the step has elapsed, the outdoor air and the outdoor determines the temperature difference of the heat exchanger, and the determination result, if the absolute value of the temperature difference between set temperature difference is less than said second solenoid Closing the valve; And (d) gradually decreasing an opening degree of the main expansion valve after a predetermined time (t ₂ ) has elapsed from the step (c). The method according to claim 1, Switching method. The method of claim 3, Wherein the step (d) further comprises increasing the rotational speed of the indoor ventilation fan. ≪ RTI ID = 0.0 > [10] < / RTI > 5. The method of claim 4, Wherein the step (c) is repeated a predetermined number of times when the absolute value of the temperature difference between the outdoor air and the outdoor heat exchanger exceeds the set temperature difference in the step (c). The air- Of the injection mode.

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