KR20100062079A - Injection type heat pump air-conditioner and the converting method for injection mode thereof - Google Patents

Abstract

PURPOSE: An injection type air conditioner for cooling and heating, capable of stably operating an injection mode, and a method for converting to the injection mode thereof are provided to prevent the rapid decreasing of the pressure in an intake port of a compressor in the initial injection mode of the air conditioner. CONSTITUTION: An injection type air conditioner for cooling and heating comprise: a compressor; an indoor heat exchanger; an outdoor heat exchanger; a main expansion valve(40); an injection pipe(90) which supplies a vapor refrigerant in a liquid receiver which is included between the indoor heat exchanger and the main expansion valve to an injection port which is formed in the compressor; and a bypass pipe(100) which selectively flows a part of the refrigerant which is discharged from an outlet of the compressor to an inlet of the compressor. A first solenoid valve(91) and a second solenoid valve(101) are installed in the injection pipe and the bypass pipe, respectively, and the second solenoid valve is opened in an injection mode of the air conditioner while the first solenoid valve is opened.

Description

INJECTION TYPE HEAT PUMP AIR-CONDITIONER AND THE CONVERTING METHOD FOR INJECTION MODE THEREOF}

The present invention prevents the inlet side pressure of the compressor from dropping rapidly at the initial stage of the injection mode during operation of the air conditioner, and the air-conditioning combined injection type air conditioner and the air that allow the injection mode to proceed more stably. It relates to an injection mode switching method of the harmonic.

In general, a heat pump air conditioner combines cooling and heating by reversibly using a transfer mechanism for heat that is transferred to a refrigeration cycle consisting of compression, condensation, depressurization, and evaporation of a refrigerant.

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

As shown, the conventional air-conditioning combined heat pump air conditioner has a compressor 10, an indoor side heat exchanger 20, an indoor side blower fan 21, an outdoor side heat exchanger 30, and an outdoor side blower fan 31. , The main expansion valve 40 and the four-way valve 50, the accumulator 110 is configured to include.

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 the gas-cooled state through the discharge port 12 in a high-temperature high-pressure gas state.

In addition, 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 air conditioner is cooled. And the switching operation to change the flow of the refrigerant in accordance with the heating operation mode.

On the other hand, the indoor heat exchanger 20 is located in the room, in the cooling operation mode serves as an evaporator to evaporate the low-temperature low-pressure liquid refrigerant in the gaseous state, in the heating operation mode the high temperature and high pressure gaseous refrigerant at room temperature (I) It acts as a condenser to condense to a high pressure liquid state and acts as a heat exchanger with the surrounding air in response to changes in enthalpy of the refrigerant.

In addition, the indoor blower fan 21 is installed on the side of the indoor heat exchanger 20 to promote the heat exchange action as an evaporator or a condenser of the indoor heat exchanger 20 and to generate the cold or hot air necessary for the room. It works.

On the other hand, the main expansion valve 40 is connected between the indoor heat exchanger 20 and the outdoor heat exchanger (30) for reducing the room temperature high pressure liquid refrigerant delivered from any one side to a low temperature low pressure liquid state As such, it is preferable to apply the valve to which the opening degree is electronically controlled.

In addition, the outdoor side heat exchanger 30 is installed on the outdoor side as opposed to the indoor side heat exchanger 20 and performs heat exchange with the surrounding air as a condenser during the cooling operation and as an evaporator during the heating operation.

In addition, the outdoor blower fan 31 is installed on the side of the outdoor heat exchanger 30 and is operated to promote heat exchange (as a condenser or evaporator) of the outdoor heat exchanger 30.

On the other hand, the accumulator 110 filters the refrigerant remaining in a liquid state without phase change from the refrigerant flowing into the compressor 10 from the four-way valve 50 and at the same time serves to supply oil to the compressor 10 side.

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

Recently, in order to improve the cooling or heating capability of the conventional heat pump air conditioner as described above, the injection (injection) method of the compressor is introduced, as shown in Figure 1, the indoor heat exchanger (20) And a portion between the main expansion valve 40 and the sub capillary tube 60 and the receiver 70 are configured to further include.

The injection type heat pump air conditioner is a liquid refrigerant contained in the receiver 70 of the refrigerant passing through the indoor heat exchanger 20 during the heating operation, and the outdoor heat exchanger via the main expansion valve 40. 30, and the refrigerant in the gas phase accommodated in the receiver 70 is injected into the injection port 13 of the compressor 10.

Therefore, it is possible to improve the heating capacity of the air conditioner by increasing the circulation amount of the refrigerant circulating in the air conditioner cycle.

However, in the conventional injection mode, the compression ratio of the compressor, that is, the refrigerant pressure ratio of the compressor suction port side to the refrigerant pressure of the compressor discharge port side increases rapidly as the pressure on the compressor inlet side decreases more rapidly than the normal operation state rather than the injection mode. In this case, a system malfunction of the air conditioner occurs, causing a problem.

In addition, during the injection mode of the air conditioner, the temperature of the indoor heat exchanger 20 is increased as compared to the normal operation state, so that the cycle of the air conditioner becomes unstable, thereby causing a malfunction of the system.

An object of the present invention has been made to solve the above problems, to prevent the pressure of the compressor inlet side drops sharply during the initial injection mode of the air conditioner, and to prevent the malfunction of the air conditioner system to occur. It is to provide an air-conditioning combined injection type air conditioner and an injection mode switching method of the air conditioner.

In order to achieve the above object, the air-conditioning combined type air conditioner of the present invention includes a compressor, an indoor side heat exchanger, an outdoor side heat exchanger, and a main expansion valve, between the indoor side heat exchanger and the main expansion valve. And an injection pipe for supplying the gaseous refrigerant of the receiver to the injection port formed in the compressor, 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. do.

The first and second solenoid valves are installed 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.

In order to achieve the object as described above, the injection mode switching method of the combined air-conditioning injection type air conditioner of the present invention is the injection mode switching method of the combined air-conditioning injection type air conditioner, (a) heating of the air conditioner Determining a driving mode; (b) fully opening the main expansion valve and opening the first and second solenoid valves when it is determined in the rapid heating mode in step (a); (c) determining the temperature difference between the outside heat exchanger and the outdoor heat exchanger after a predetermined time (t ₁ ) has elapsed from step (b), and if the absolute value of the temperature difference is less than or equal to a set temperature difference, the second solenoid Closing the valve; And (d) stepwise reducing the opening degree of the main expansion valve after a predetermined time (t ₂ ) has elapsed from the step (c).

In addition, the step (d) is characterized in that it further comprises the step of increasing the rotational speed of the indoor blower fan.

Further, in the step (c), when the absolute value of the temperature difference between the outdoor and the outdoor side heat exchanger exceeds the set temperature difference, the step (c) is repeated by a predetermined number of times.

According to the above-described air-conditioning-injection type air conditioner according to the present invention and an injection mode switching method of the air conditioner, the air conditioner system is prevented from suddenly decreasing the pressure at the inlet side of the compressor during the initial injection mode of the air conditioner. There is an effect that can prevent the malfunction of the.

In addition, if the temperature difference between the outside and the outdoor heat exchanger exceeds the set temperature difference during the injection mode of the air conditioner, the refrigerant passing through the bypass pipe and the accumulator continues to flow into the inlet side of the compressor to increase the temperature of the indoor heat exchanger. By preventing the effect of the abnormal operation of the air conditioner according to the rise of the temperature of the indoor heat exchanger is effective.

In addition, when the injection mode is in progress, the opening degree of the main expansion valve is decreased step by step and the rotational speed of the indoor blower fan is increased. This prevents the system from operating abnormally and at the same time has the effect of making the injection mode stable.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention will be described in detail, the same reference numerals will be given to the same configuration as the prior art.

2 is a block diagram showing an air conditioner according to an embodiment of the present invention.

As shown in FIG. 2, the air-conditioning combined injection type air conditioner according to the embodiment of the present invention includes a compressor 10, an indoor side heat exchanger 20, an outdoor side heat exchanger 30, and a main expansion valve 40. And a four-way valve 50, and is configured to phase change while the refrigerant circulates through the pipes connecting the components and the components.

The compressor 10 compresses the low-temperature, low-pressure gaseous refrigerant sucked from the suction port 11 to be discharged through the discharge port 12 in a high-temperature, high-pressure gas state.

In addition, the indoor side and the outdoor side heat exchangers 20 and 30 are connected to the compressor 10 by pipes to exchange heat with outside air.

In addition, the main expansion valve 40 is connected between the indoor side heat exchanger 20 and the outdoor side heat exchanger 30 to reduce the high pressure liquid refrigerant to a low pressure liquid phase.

On the other hand, as shown in Figure 2, the pipe between the indoor heat exchanger 20 and the outdoor heat exchanger 30 is provided with a sub capillary tube 60 connected in series with the main expansion valve 40 The receiver 70 is provided between the main expansion valve 40 and the sub capillary tube 60 to separately classify the refrigerant in the gas state and the refrigerant in the liquid state.

In addition, the one-way valve 80 is connected in parallel with the sub-capillary tube 60, is opened during the cooling operation of the air conditioner, and is closed during the heating operation, and thus does not form a flow path. And the piping between the outdoor side heat exchanger 30.

Meanwhile, the four-way valve 50 connects the discharge port 12 of the compressor 10 to the indoor side heat exchanger 20 or the outdoor side heat exchanger 30 to change the refrigerant flow path when the air conditioner is converted to air conditioning. Is switched to.

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

On the contrary, during the heating operation of the air conditioner, the refrigerant discharged through the discharge port of the compressor 10 is the opposite of the above-described indoor side heat exchanger 20, sub capillary tube 60, main expansion valve 40, and outdoor side heat exchanger. It cycles through the group 30 etc. sequentially.

Therefore, the indoor heat exchanger 20 serves as an evaporator during the cooling operation of the air conditioner, and the indoor heat exchanger 20 during the heating operation is configured to serve as a condenser.

On the other hand, the indoor side blower fan 21 and the outdoor blower fan 31 are provided in the side part of the indoor side and the outdoor side heat exchanger 20,30 so that heat exchange efficiency may be improved.

In addition, the air conditioner to measure the temperature of each component of the air conditioner, including the indoor, outdoor heat exchanger (20,30), the temperature of the pipe connecting the components, the temperature of the outside air, the temperature of the room It is equipped with a number of temperature sensors.

In addition, the injection pipe 90 is formed to supply the refrigerant in the gas phase of 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 circulation efficiency of the refrigerant circulating in the air conditioner cycle when the heating load is greater than normal during the heating operation of the air conditioner, the receiver 70 ), The gaseous refrigerant is naturally introduced into the injection port 13 of the compressor 10 through the injection pipe 90 due to the difference in pressure with the compressor 10.

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

In addition, the accumulator to filter the refrigerant remaining in the liquid state without phase change in the gas phase from the refrigerant flowing into the suction port 11 of the compressor 10 from the four-way valve 50 and at the same time to supply oil to the compressor 10 side 110 is provided.

On the other hand, when the refrigerant flows into the compressor 10 through the injection pipe 90, the conventional air conditioner is the refrigerant flowing into the compressor 10 and the refrigerant discharged into the compressor 10 due to the increase in the refrigerant suction amount of the compressor 10 instantaneously Depending on the flow rate difference, the pressure ratio between the suction port 11 and the discharge port 12 of the compressor 10 may increase rapidly.

As a result, the load increase of the motor constituting the compressor 10 and the wear of the mechanism part cause the reliability problem of the main parts, and furthermore, the operation of the protection mode of the air conditioner or the temperature of the indoor heat exchanger to prevent this. There was a problem that a malfunction of the air conditioner system due to the sudden rise and the like occurs.

In order to solve this problem, in the embodiment of the present invention, as shown in FIG. 2, at least a part of the refrigerant discharged from the discharge port 12 of the compressor 10 is passed through the accumulator 110 in the injection mode of the air conditioner. By passing through the inlet 11 of the compressor 10, the bypass pipe 100 is formed to prevent the sudden rise of the above-described pressure ratio.

That is, the air conditioner according to the embodiment of the present invention opens the bypass pipe 100 at the beginning of the injection mode to increase the refrigerant suction amount of the compressor 10 so that the compressor according to the sudden decrease in the suction pressure of the compressor 10 ( The pressure ratio of 10) can be prevented from rising, and as a result, the malfunction of the air conditioner system can be prevented.

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

In this case, the second solenoid valve 101 may be configured to open at the same time as the first solenoid valve 91 or to be opened with a time difference as necessary.

That is, whether or not the first and second solenoid valves 91 and 101 are opened is made by signal transmission of a control unit according to air conditioning selection of the air conditioner.

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

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

As shown, the control unit 120 is a signal of the input unit 121 receiving the air conditioning operation mode conversion signal of the air conditioner through the user's switch operation, the temperature of the outdoor heat exchanger 30, the temperature of the outside air And it is made to receive the measured values of the temperature sensors (122, 123, 124) for measuring the temperature of the room, respectively.

In addition, the control unit 120 determines the input signal input, the main expansion valve 40, the four-way valve 50, one-way valve 80 and the first, second solenoid valves (91, 101) shown in FIG. Outputs a control signal for controlling the operation.

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

First, when the air conditioner is operated by applying power to the air conditioner (S10), the controller 120 determines whether the operation mode of the air conditioner is the cooling mode or the heating mode (S20). It may be determined using the signal of 121.

Here, the refrigerant when the operation mode determined by the control unit 120 is the cooling mode, the compressor 10, the outdoor side heat exchanger 30, the main expansion valve 40, the one-way valve 80 shown in FIG. ) And the indoor side heat exchanger 20 in order to circulate the cycle of the air conditioner.

On the other hand, when the determined operation mode is the heating mode, the refrigerant is the compressor 10, the indoor side heat exchanger 20, the sub capillary tube 60, the main expansion valve 40, and the outdoor side heat exchanger illustrated in FIG. 2. The cycle of the air conditioner is cycled in the order of (30).

On the other hand, during the heating mode operation of the air conditioner, the air conditioner is provided with a normal heating mode to enable a normal heating operation, and also measured by the user's selection or the temperature sensor (123, 124) through the input unit 121 When the temperature difference between the outside and the room is more than a predetermined level, a rapid heating mode is provided to increase the circulation amount of the refrigerant by the control signal of the controller 120.

When the step S20 is completed, the control unit 120 determines whether the heating operation mode of the air conditioner described above is a normal heating mode or a rapid heating mode (S21).

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

Accordingly, the gaseous refrigerant contained in the receiver 70 and having a pressure state higher than that of the inlet 11 of the compressor 10 naturally flows into the injection port 13 of the compressor 10 by the pressure difference. .

In addition, 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 pipe 100.

Therefore, the air conditioner according to the embodiment of the present invention can prevent the phenomenon in which the pressure of the inlet port 11 of the compressor 10 decreases suddenly while the injection pipe 90 is opened.

When the step S30 is completed, the controller 120 determines whether a predetermined time t ₁ has elapsed (S40).

If it is determined in step S40 that the predetermined time t ₁ has elapsed, the controller 120 determines whether the absolute value of the temperature difference between the outside air temperature and the outdoor side heat exchanger 30 is equal to or less than the set temperature difference ΔT _SET . S41).

On the other hand, if the predetermined time t ₁ has not elapsed in step S40, the control unit 120 repeats step S40.

As described above, as the refrigerant suction amount of the compressor 10 rapidly increases due to the opening of the injection pipe 90, the cycle of the initial air conditioner of the injection mode may become unstable. ₁ ) means the set time until the refrigerant is stabilized while the refrigerant cycles through the air conditioner cycle approximately 2 ~ 3 times after the injection mode is executed.

As a result of the determination in step S41, when the absolute value of the temperature difference between the outdoor and outdoor heat exchanger 30 is less than or equal to the set temperature difference ΔT _SET , the controller 120 determines that the cycle of the air conditioner in the injection mode is in a stable state. By outputting the control signal to close the second solenoid valve 101 (S42).

In detail, when the absolute value of the temperature difference between the outside air temperature and the outdoor side heat exchanger 30 is equal to or less than the set temperature difference ΔT _SET in step S41, when the second solenoid valve 101 is closed, the first solenoid valve 91 is opened. This results in an increase in temperature of the indoor heat exchanger 20, thereby increasing the heating efficiency of the air conditioner.

On the other hand, if the absolute value of the temperature difference between the outdoor and the outdoor side heat exchanger 30 exceeds the set temperature difference ΔT _SET in step S41, the control unit 120 is in an unstable cycle of the air conditioner in the injection mode. It is determined that the second solenoid valve 101 to maintain the open state (S43, S44).

At this time, the control unit 120 repeats the steps S40, S43, S44 by the preset cycle number C, and performs the step S50 described later when the cycle cycle number of the refrigerant exceeds the set cycle number C. do.

When the step S42 is completed, the controller 120 determines whether a predetermined time t ₂ has elapsed (S50).

If it is determined in step S50 that the predetermined time t ₂ has elapsed, the control unit 120 transmits a control signal to the main expansion valve 40 to decrease the opening degree of the main expansion valve 40 step by step. The control signal is transmitted to increase the rotation speed of the indoor blower fan 21 (S51).

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

On the other hand, in the step S51 the reduced blowing amount of the indoor blower fan 21 is to be at least more than the mid-wind or strong wind state not a weak wind state.

This makes it possible to prevent abnormal operation of the air conditioner cycle due to the high temperature of the indoor heat exchanger 20 having a relatively high temperature state compared to 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).

As a result of the determination in step S60, if the injection mode is maintained, the control unit 120 determines whether the OFF signal of the air conditioner is input (S70). Repeat step S51.

On the other hand, if the determination result of step S60, if not in the injection mode to perform the step S20.

Although the preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to such specific embodiments, and those skilled in the art may appropriately change within the scope described in the claims of the present invention. Or modifications may be possible.

1 is a configuration diagram showing a conventional air conditioner.

2 is a block diagram showing an air conditioner according to an embodiment of the present invention.

Figure 3 is a block diagram showing the configuration of switching the injection mode of the 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 exemplary embodiment of the present invention.

*** Explanation of symbols for the main parts of the drawing ***

10: Compressor 11: Intake

12: discharge port 13: injection port

20: indoor side heat exchanger 21: indoor side blower

30: Outdoor side heat exchanger 31: Outdoor side blower fan

40: main expansion valve 50: four-way valve

60: sub capillary 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: outside heat exchanger temperature sensor 123: outside temperature sensor

124: room temperature sensor

Claims (5)

Including compressor, indoor heat exchanger, outdoor heat exchanger and main expansion valve, An injection pipe for supplying a gaseous refrigerant of a receiver provided between the indoor heat exchanger and the main expansion valve to an injection port formed in the compressor; And And a bypass pipe for selectively introducing at least a portion of the refrigerant discharged from the discharge port of the compressor to the suction port of the compressor. The method of claim 1, First and second solenoid valves are installed in the injection pipe and the bypass pipe, respectively, wherein the second solenoid valve is opened in the injection mode of the air conditioner in which the first solenoid valve is opened. Combined injection type air conditioner. In the injection mode switching method of the air-conditioning combined injection type air conditioner of claim 2, (a) determining a heating operation mode of the air conditioner; (b) fully opening the main expansion valve and opening the first and second solenoid valves when it is determined in the rapid heating mode in step (a); (c) determining the temperature difference between the outside heat exchanger and the outdoor heat exchanger after a predetermined time (t ₁ ) has elapsed from step (b), and if the absolute value of the temperature difference is less than or equal to a set temperature difference, the second solenoid Closing the valve; And (d) the injection mode of the air-conditioning and injection type air conditioner, comprising the step of decreasing the opening degree of the main expansion valve step by step after a predetermined time (t ₂ ) from step (c). How to switch. The method of claim 3, Wherein step (d) further comprises the step of increasing the rotational speed of the indoor blowing fan injection mode switching method of the combined heating and cooling type air conditioner. The method of claim 4, wherein In the step (c), when the absolute value of the temperature difference between the outdoor and outdoor side heat exchanger exceeds the set temperature difference, the step (c) is repeated for a predetermined number of times, the air-conditioning combined type air conditioner How to switch injection mode.

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