KR20070076305A - Control method of air conditioner - Google Patents

Abstract

A control method of an air conditioner is provided to sufficiently realize cooling performance of each indoor unit by preventing the deterioration of cooling performance of some indoor units. A control method of an air conditioner includes the steps of passing a refrigerant with keeping a predetermined initial opening ratio of an electronic expansion valve(S100), determining whether an initial opening ratio maintaining time is over a predetermined time(S101), controlling the opening ratio of the electronic expansion valve to keep a difference of a T1 and a T2 within a predetermined range, if the initial opening ratio maintaining time is over the predetermined time(S102), wherein the T1 is a temperature of refrigerant flowing to a compressor, and the T2 is a temperature of a first indoor heat exchanger determining whether the difference of the T1 and the T2 is within a first predetermined range(S103), keeping the current opening ratio of the electronic expansion valve, if the difference of the T1 and the T2 is within the first predetermined range, and if not, controlling the current opening ratio(S104), determining if a difference of a T4 and a T5 is within a second predetermined range, wherein the T4 is a discharging temperature of the first indoor heat exchanger, and the T5 is a discharging temperature of a second indoor heat exchanger(S105), keeping the current opening ratio whether the difference of the T4 and the T5 is within the second predetermined range, and if not, controlling the current opening ratio(S106), determining whether a difference of the T2 and the T3 is within a third predetermined range(S107), and keep the current opening ratio if the difference of the T2 and the T3 is within the third predetermined range(S108).

Description

Control Method of Air Conditioner

1 is a schematic diagram showing a refrigerant cycle of an air conditioner according to the present invention.

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

3 is a control flowchart of an air conditioner according to the present invention.

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

18: solenoid valve 20: solenoid valve

22: capillary tube 40a: compressor suction temperature sensor

40b: first indoor heat exchanger temperature sensor 40c: second indoor heat exchanger temperature sensor

40d: 1st indoor heat exchanger discharge temperature sensor 40e: 2nd indoor heat exchanger temperature sensor

The present invention relates to a control method of an air conditioner, and more particularly, in an air conditioner including a plurality of indoor units, a control method of an air conditioner for preventing a decrease in cooling capacity occurring in some indoor units is provided.

An air conditioner is a device that allows the user to adjust the temperature of indoor air to a desired temperature by using a refrigerant cycle of compression, condensation, expansion, and evaporation, and according to the structure of the air conditioner, that is, whether the indoor unit and the outdoor unit are separated. The air conditioner is divided into a separate air conditioner and an integrated air conditioner, and the present invention relates to a multi-type or multi-chamber air conditioner that provides a plurality of indoor units to one outdoor unit among the separate air conditioners to facilitate air-conditioning for various spaces.

The conventional air conditioner is separated into one outdoor unit and a plurality of indoor units, and the outdoor unit includes a compressor for compressing the refrigerant at high temperature and high pressure, an outdoor heat exchanger, a blower fan, and condensing the refrigerant having high temperature and high pressure discharged to the compressor at room temperature and high pressure. Electronic expansion valves and capillaries for expanding the condensed refrigerant were provided, and a plurality of indoor units were each provided with an indoor heat exchanger and a blowing fan.

Some of the plurality of indoor heat exchangers are connected to the electromagnetic expansion valve, and some are connected to the capillary tube. At this time, an on / off solenoid valve for connecting / blocking the inflow of the refrigerant is installed in front of the capillary tube. In the indoor heat exchanger and compressor connected to the electronic expansion valve, a temperature sensor was arranged on the suction side.

Therefore, to determine the temperature difference between the indoor heat exchanger connected to the electromagnetic expansion valve and the refrigerant of the suction part of the compressor, the opening degree of the electromagnetic expansion valve is adjusted to adjust the superheat degree of the electromagnetic expansion valve. When the temperature of the gas rises, the opening degree of the electromagnetic expansion valve is increased in order to add more refrigerant.

However, in this case, when the amount of refrigerant flowing into the indoor heat exchanger connected to the electromagnetic expansion valve is increased by increasing the opening degree of the electromagnetic expansion valve, there is a problem that the amount of refrigerant flowing into the room heat exchanger connected to the capillary tube is relatively decreased.

That is, the main target of the conventional air conditioner was the inflow rate of the refrigerant of the indoor unit connected to the electromagnetic expansion valve. Therefore, the refrigerant inflow amount of the indoor unit connected to the capillary tube is a dependent variable of the refrigerant inflow amount of the indoor unit connected to the electromagnetic expansion valve. When a large amount of refrigerant is introduced into the indoor unit connected to the valve, the amount of refrigerant inflow of the indoor unit connected to the capillary tube is greatly reduced, resulting in a significant decrease in the cooling capacity there.

The present invention is to solve this problem, in an air conditioner having a plurality of indoor units, to prevent the refrigerant from being biased into some indoor units, the cooling capacity of each indoor unit in each indoor unit without reducing the cooling capacity in the remaining indoor units An object of the present invention is to provide a control method of an air conditioner that can be implemented so that the amount of refrigerant suitable for the present invention can be distributed.

In order to achieve the above object, the present invention provides a control method of an air conditioner including a compressor, a plurality of indoor heat exchangers, an electronic expansion valve connected to some indoor heat exchangers, a solenoid valve and a capillary tube connected to some indoor heat exchangers,

Comparing the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected with the refrigerant suction temperature of the compressor, and adjusting the opening degree of the electromagnetic expansion valve according to the result; Comparing the discharge refrigerant temperature of the indoor heat exchanger connected to the electromagnetic expansion valve with the discharge refrigerant temperature of the indoor heat exchanger connected to the solenoid valve and the capillary tube, and adjusting the opening degree of the electromagnetic expansion valve according to the result; ; And comparing the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected with the temperature of the indoor heat exchanger to which the solenoid valve and the capillary tube are connected, and adjusting the opening degree of the electromagnetic expansion valve according to the result. .

More specifically, it is determined whether the difference between the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected and the refrigerant suction temperature of the compressor is within the first setting range, and when the temperature difference is out of the first setting range. The amount of refrigerant passing through the electromagnetic expansion valve is increased or decreased so that the temperature difference can be formed within the first setting range by adjusting the opening degree of the electromagnetic expansion valve.

The difference between the discharge refrigerant temperature of the indoor heat exchanger connected to the electromagnetic expansion valve and the discharge refrigerant temperature of the indoor heat exchanger connected to the solenoid valve and the capillary tube is determined to be within the second setting range, and the temperature difference is set to the second setting. When the range is out of range, the opening degree of the electromagnetic expansion valve is adjusted to increase or decrease the amount of refrigerant passing through the electromagnetic expansion valve so that a temperature difference can be formed within the second setting range.

In addition, it is determined whether the difference between the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected and the temperature of the indoor heat exchanger to which the solenoid valve and the capillary tube are connected is within the third setting range, and the temperature difference is out of the third setting range. In one case, the amount of refrigerant passing through the electromagnetic expansion valve is increased or decreased so as to adjust the opening degree of the electromagnetic expansion valve so that the temperature difference can be formed within the third set range.

Further, when the refrigerant discharge temperature of the indoor heat exchanger connected to the solenoid valve and the capillary tube is significantly higher than the refrigerant discharge temperature of the indoor heat exchanger connected to the electromagnetic expansion valve and is larger than the second set range, the opening degree of the electromagnetic expansion valve is increased. Reducing the amount of refrigerant directed to the solenoid valve and capillary.

In addition, when the temperature of the indoor heat exchanger connected to the solenoid valve and the capillary tube is significantly higher than the temperature of the indoor heat exchanger connected to the electromagnetic expansion valve and is larger than the third set range, the opening degree of the electromagnetic expansion valve is reduced to reduce the solenoid. Increasing the amount of refrigerant directed to the valve and capillary.

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

As shown in FIG. 1, the air conditioner according to the present invention is composed of an outdoor unit 10 and a plurality of indoor units 30. In this embodiment, it is shown that two indoor units are provided for convenience.

The outdoor unit 10 includes a compressor 11 for compressing a refrigerant at high temperature and high pressure, a four-way valve 12 connected to a discharge part and a suction part of the compressor 11, and a high temperature high pressure discharged from the compressor 11. The outdoor heat exchanger 14 for condensing the refrigerant of the refrigerant, and the outdoor blower fan 16 for sucking and discharging the outdoor air to the outdoor heat exchanger 14 side.

In addition, an electromagnetic expansion valve 18 and a capillary tube 22 for expanding the refrigerant condensed in the outdoor heat exchanger 14 and the capillary tube 22 are installed inside the outdoor unit 10. In particular, the capillary tube 22 is provided with the capillary tube. An on / off solenoid valve 20 capable of intermitting the refrigerant flowing into the (22) side is provided.

Each of these components is connected by a refrigerant pipe 42 to allow the refrigerant to flow through the refrigerant pipe 42 to form a refrigerant cycle, wherein the outdoor heat exchanger 14 of the refrigerant pipe 42 is formed. The refrigerant pipe 42 disposed on the discharge side of the c) is branched into two branches.

 One of them is a first refrigerant suction pipe 43a connected to the electromagnetic expansion valve 18 and connected to the first chamber 30a, and the other one is provided with the solenoid valve 20 and the capillary tube 22. It is a second refrigerant suction pipe 43b.

The first refrigerant suction pipe 43a is connected to the suction part of the first indoor heat exchanger 32, and the second refrigerant suction pipe 43b is connected to the suction part of the second indoor heat exchanger 34, The first indoor heat exchanger 32 and the second indoor heat exchanger 34 have a first indoor heat exchanger temperature sensor 40b capable of measuring respective temperatures, and a second indoor heat exchanger temperature sensor 40c. Is installed.

In addition, the discharge portion of the first indoor heat exchanger 32 and the discharge portion of the second indoor heat exchanger 34 respectively guide the flow of the refrigerant so that the discharged refrigerant flows back into the compressor 11. The first refrigerant discharge pipe 44a and the second refrigerant discharge pipe 44b connected to the refrigerant pipe 42 are disposed, and the first internal heat exchanger 32 is disposed in the first refrigerant discharge pipe 44a. A first indoor heat exchanger discharge temperature sensor (40d) capable of measuring the temperature of the refrigerant discharged from the air is provided, and the second refrigerant discharge pipe (44b) of the refrigerant discharged from the second indoor heat exchanger (34) is installed. A second indoor heat exchanger discharge temperature sensor 40e capable of measuring the temperature is provided.

In addition, the suction part of the compressor 11 is provided with a compressor suction temperature sensor 40a for measuring the temperature of the refrigerant to be sucked.

Therefore, not only the suction temperature of the refrigerant flowing into the compressor 11 and the temperature of the first indoor heat exchanger 32 by this configuration, but also the temperature of the second indoor heat exchanger 34 and the first and second temperatures. The temperature of the refrigerant discharged from the indoor heat exchangers 32 and 34, respectively, is measured, and after each temperature data is inputted to the control unit to be described later and compared, the degree of opening of the electromagnetic expansion valve 18 is changed according to the temperature difference. By controlling the amount of the refrigerant flowing into the first and second indoor heat exchangers (32, 34) is adjusted, it is possible to distribute the amount of refrigerant suitable for the cooling capacity of each indoor unit (30a, 30b).

As shown in Figure 2, the air conditioner according to the present invention is provided with a control unit 60, the input of the control unit 60, the compressor suction temperature sensor 40a, the first, second indoor heat exchanger temperature sensor 40b and 40c, first and second indoor heat exchanger discharge temperature sensors 40d and 40e, a power supply unit 50 for supplying power, and a mode selection unit 52 for selecting an operation mode of the air conditioner Is connected.

In addition, a compressor driving unit 11a for driving the compressor 11 (see FIG. 1) at the output end of the control unit 60 and a tank expansion valve driving unit for adjusting the opening degree of the electromagnetic expansion valve 18 (see FIG. 1). 18a and a solenoid valve 20a for closing the solenoid valve 20 (see FIG. 1) are connected to the controller 60 according to the respective temperature values input to the controller 60. Will be driven by

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

As shown in FIG. 3, when the operating condition of the air conditioner according to the present invention is selected as cooling and starts to operate, the electromagnetic expansion valve passes the refrigerant while maintaining a predetermined initial opening degree to the controller ( S101), the controller determines whether the initial opening degree maintenance time of the electronic expansion valve has elapsed a predetermined time (S012), and if the setting time has not elapsed, maintains the initial opening as it is, and if the setting time has elapsed, the electronic expansion valve The opening degree of the electromagnetic expansion valve is adjusted by comparing the suction temperature (T1) of the refrigerant sucked into the compressor with the temperature (T2) of the first indoor heat exchanger. It is to adjust the amount of refrigerant passing through the electromagnetic expansion valve so that the difference value (T1-T2) of the temperature is maintained in a constant range (S102).

Therefore, the difference value T1-T2 between the suction temperature T1 of the refrigerant sucked into the compressor and the temperature T2 of the first indoor heat exchanger is maintained within the first set range while adjusting the opening degree of the electromagnetic expansion valve. If so, the opening degree of the current electromagnetic expansion valve is maintained so that the state can be continued, but if it is determined that it is out of the first setting range, the opening degree of the electromagnetic expansion valve is again adjusted (S103, S104).

After the above process, by detecting the discharge temperature (T4) of the first indoor heat exchanger and the discharge temperature (T5) of the second indoor heat exchanger, the difference value (T4-T5) of the two temperatures is preliminarily provided to the control unit. It is determined whether or not it is within the input second set range (S105).

In this determination step, if it is determined that the difference value (T4-T5) between the two temperatures is out of the second set range, the opening degree of the electromagnetic expansion valve is adjusted again, otherwise, the opening degree of the state is maintained. S106).

As such, the process of determining whether the first set range is maintained between the suction temperature of the compressor and the temperature difference (T1-T2) of the first indoor heat exchanger, and the first indoor heat exchanger discharge temperature and the second indoor heat exchanger discharge After the process of determining whether the temperature difference T4-T5 is maintained in the second set range, the temperature T2 of the first indoor heat exchanger and the temperature T3 of the second indoor heat exchanger are sensed. It is determined whether or not the difference value T2-T3 is within the third input range previously input (S107).

Thus, if it is determined that it is within the third set range, the opening degree of the electromagnetic expansion valve in that state is maintained as it is, otherwise, the difference value T2-T3 of both temperatures is within the third set range. The amount of refrigerant flowing into the first indoor heat exchanger and the second indoor heat exchanger is changed by changing the opening value of the electromagnetic expansion valve.

That is, the refrigerant is not biased in some indoor heat exchangers so that the difference values T1-T2, T4-T5, and T2-T3 of the respective temperatures with respect to the five temperature values T1 to T5 are maintained in a constant range. The opening degree of the electromagnetic expansion valve is adjusted.

However, at this time, the reason for controlling the temperature difference (T2-T3) of the first and second indoor heat exchanger after controlling the discharge temperature difference (T4-T5) of the first and second indoor heat exchanger is Since the change in the temperature of the refrigerant discharged from each indoor heat exchanger is greater than the change in the temperature of the heat exchanger, when the difference value (T4-T5) of the discharge temperature of the first and second indoor heat exchangers is stabilized to a predetermined range, This is because it is more convenient and the time required for stabilizing the difference value (T2-T3) of the temperature of the 1,2-room heat exchanger.

1 to 3, to give a specific example, the first setting range is set to 3 ± 2 ℃, the second and the third setting range is set equal to 0 ± 2 ℃, the initial opening degree of the electromagnetic expansion valve In the case where the holding time is set to 5 minutes, first, power is supplied to the air conditioner through the power supply unit 50, and a cooling mode is selected by the mode selection unit 52 to input a constant temperature desired by the user. The electronic expansion valve 18 maintains a predetermined initial opening degree, and when the initial opening holding time has elapsed for 5 minutes, the electromagnetic expansion valve 18 is out of the initial opening holding state and its opening degree is adjusted. Due to the adjustment of the opening degree, the control unit 60 determines the difference between the temperature T1 detected by the compressor suction temperature sensor 40a and the temperature T2 detected by the first indoor heat exchanger temperature sensor 40b. T1-T2) out of the first setting range Determine if you are.

At this time, if the T1-T2 value is maintained within the range of 3 ± 2 ℃ maintains the current opening degree of the electromagnetic expansion valve 18, accordingly the first chamber (30a) and the second chamber (30b) A certain amount of refrigerant is introduced into each.

However, if the value of the first indoor heat exchanger temperature (T2) is increased so that the value of T1-T2 is outside the range of 3 ± 2 ° C., this is a signal that more refrigerant should be introduced into the first indoor heat exchanger (32). Therefore, the opening degree of the electromagnetic expansion valve 18 is increased so that the amount of refrigerant introduced into the first indoor heat exchanger 32 is increased, and the amount of refrigerant introduced into the second indoor heat exchanger 34 is relatively reduced. do.

As such, when the opening degree of the electromagnetic expansion valve 18 is maintained or adjusted to maintain the T1-T2 value at 3 ± 2 ° C., which is the first setting range, the discharge temperature T4 of the first indoor heat exchanger is then obtained. ) And the discharge temperature T5 of the second indoor heat exchanger, and determines whether the difference value T4-T5 of both temperatures is maintained at 0 ± 2 ° C. which is the second set range.

If it is determined by the above judgment that the second set range is maintained, the opening degree of the electromagnetic expansion valve 18 is maintained, but it is determined that the second set range is out of the second set range, that is, for example, the electronic expansion in the previous step. By increasing the opening value of the valve 18, the amount of refrigerant flowing into the second indoor heat exchanger 34 is relatively decreased, so that the temperature of the refrigerant discharged from the second indoor heat exchanger 34 is increased, thereby T4. When the value of -T5 is out of 0 ± 2 ° C, the opening degree of the electromagnetic expansion valve 18 in the electromagnetic expansion valve is reduced in order to prevent the cooling capacity of the second chamber 30b from decreasing.

Therefore, when the opening degree of the electromagnetic expansion valve 18 decreases, the amount of refrigerant flowing toward the second indoor heat exchanger 34 is increased, so that the discharge temperature T4 of the first indoor heat exchanger and the second indoor heat exchanger are increased. Is different from the discharge temperature T5 within the second set range.

As such, if the requirements for the first set range and the second set range are satisfied, the temperature T2 of the first indoor heat exchanger 32 and the temperature T3 of the second indoor heat exchanger 34 are satisfied. ), And determining whether or not the temperature difference (T2-T3) is maintained within the third set range, that is, 0 ± 2 ℃, by maintaining or adjusting the opening degree of the electromagnetic expansion valve 18, Each indoor unit (30a, 30b) is to distribute the inflow of the refrigerant to implement the cooling capacity for each.

As described above, the temperature of the suction part of the compressor 18, in detail, the temperature T1 of the refrigerant sucked into the compressor 18 and the temperature T2 of the first indoor heat exchanger 32 are compared. The discharge temperature T4 of the first indoor heat exchanger 32 is compared with the discharge temperature T5 of the second indoor heat exchanger 34, in addition to judging and adjusting the opening degree of the electromagnetic expansion valve 18. By judging and comparing the temperatures of the first and second indoor heat exchangers (32, 34) to adjust the opening degree of the electromagnetic expansion valve (18) to control the difference between the temperatures within a certain range of the refrigerant in some indoor units Is prevented from excessively flowing, so that the proper cooling capacity can be implemented in each indoor unit.

According to the present invention, in the air conditioner provided with a plurality of indoor units, when the amount of the refrigerant flowing into each indoor unit, the problem caused by the refrigerant flowing in only a part of the indoor unit, that is, the other indoor unit By reducing the amount of the refrigerant relatively, it is possible to solve the problem that the cooling is significantly lower than the cooling capacity that can be implemented in the indoor unit.

Therefore, even when driving a plurality of indoor units at the same time, there is an effect that each indoor unit can fully implement its own cooling capacity by preventing the lowering of the cooling capacity in some indoor units.

Claims (6)

In a control method of an air conditioner comprising a compressor, a plurality of indoor heat exchanger, an electronic expansion valve connected to some indoor heat exchanger, a solenoid valve and a capillary tube connected to some indoor heat exchanger, Comparing the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected with the refrigerant suction temperature of the compressor, and adjusting the opening degree of the electromagnetic expansion valve according to the result; Comparing the discharge refrigerant temperature of the indoor heat exchanger connected to the electromagnetic expansion valve with the discharge refrigerant temperature of the indoor heat exchanger connected to the solenoid valve and the capillary, and adjusting the opening degree of the electromagnetic expansion valve according to the result; And comparing the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected with the temperature of the indoor heat exchanger to which the solenoid valve and the capillary tube are connected, and adjusting the opening degree of the electromagnetic expansion valve according to the result. Control method of air conditioner. The method of claim 1, The comparison between the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected and the refrigerant suction temperature of the compressor is within the first setting range, and when the temperature difference is out of the first setting range, And controlling the opening degree to increase or decrease the amount of refrigerant passing through the electromagnetic expansion valve so that the temperature difference can be formed within the first setting range. The method of claim 1, The difference between the discharge refrigerant temperature of the indoor heat exchanger connected to the electromagnetic expansion valve and the discharge refrigerant temperature of the indoor heat exchanger connected to the solenoid valve and the capillary tube is determined to be within the second setting range, and the temperature difference is set to the second setting range. In the case of deviation, the air conditioner controls the opening degree of the electromagnetic expansion valve to increase or decrease the amount of refrigerant passing through the electromagnetic expansion valve so that the temperature difference can be formed within the second setting range. Way. The method of claim 1, When the difference between the temperature of the indoor heat exchanger to which the electromagnetic expansion valve is connected and the temperature of the indoor heat exchanger to which the solenoid valve and the capillary tube are connected is determined to be within a third setting range, the temperature difference is out of the third setting range. And controlling the opening degree of the electromagnetic expansion valve to increase or decrease the amount of refrigerant passing through the electromagnetic expansion valve so that a temperature difference can be formed within the third set range. The method of claim 3, When the refrigerant discharge temperature of the indoor heat exchanger connected to the solenoid valve and the capillary tube is significantly higher than the refrigerant discharge temperature of the indoor heat exchanger connected to the electromagnetic expansion valve and is larger than the second set range, the opening degree of the electromagnetic expansion valve is reduced by And controlling the amount of refrigerant directed to the solenoid valve and the capillary. The method of claim 4, wherein When the temperature of the indoor heat exchanger to which the solenoid valve and the capillary tube are connected is significantly higher than the temperature of the indoor heat exchanger to which the solenoid valve is connected and larger than the third set range, the opening degree of the solenoid valve is reduced to reduce the opening degree of the solenoid valve. A control method of an air conditioner, characterized by increasing the amount of refrigerant directed to a capillary tube.

Images