KR102207303B1 - Air conditioner and controlling method of thereof - Google Patents

Abstract

The control method of an air conditioner according to an embodiment of the present invention is an air conditioner in which a plurality of indoor units installed in each room are connected to one outdoor unit, and the user desired temperature and the user's desired temperature are inputted. Obtaining a set temperature difference defined by a difference between the indoor temperature; Obtaining a virtual opening degree increment as a variable with a rate of change of the set temperature difference, which is defined as a degree that the obtained set temperature difference varies with time; And changing the opening degree of the indoor expansion valve of the corresponding room based on the obtained virtual opening degree increment.

Description

Air conditioner and its control method {AIR CONDITIONER AND CONTROLLING METHOD OF THEREOF}

The present invention relates to an air conditioner and a control method thereof.

In general, an air conditioner breathes hot air in the room through a series of refrigeration cycles consisting of compression, condensation, expansion, and evaporation, exchanging heat with a low-temperature refrigerant, and then discharging it to the room to cool the room or cool air in the room. Is sucked in and exchanged with a high-temperature refrigerant, and then discharged to the room to heat the room.

Meanwhile, an air conditioner capable of cooling and heating a plurality of indoor units (or rooms) at once by connecting several indoor units to one outdoor unit is called a multi-type air conditioner.

The multi-type air conditioner calculates a total load by summing the loads of each room in which each indoor unit is installed during initial driving, and controls the compressor to correspond to the total load, thereby discharging a refrigerant circulating in a cycle.

Here, the load of each chamber is a major factor in determining the amount of refrigerant discharged in the cycle during initial operation and the amount of refrigerant distributed to the indoor unit, so it has a great influence on the performance of the air conditioner, such as compression capacity, power consumption, and overload of the compressor. I can.

Therefore, in order to accurately calculate the load amount of each room during initial operation, the published prior literature discloses the use of factors such as the capacity of the indoor unit, the indoor temperature, the outdoor temperature, the temperature difference, the area of the indoor heat exchanger, and the air volume. Contents in which the opening degree of the indoor expansion valve corresponding to the calculated load amount of each room is adjusted are disclosed.

In addition, control using the superheat degree of the refrigerant passing through the indoor heat exchanger is started for appropriate distribution of the refrigerant circulating the indoor units installed in each room.

However, in the air conditioner disclosed in the prior literature, in the process of reaching the indoor temperature of each room to the desired temperature set by the user after the initial operation, a control that does not reflect the load release speed that varies according to the load size of each room is performed. .

Accordingly, since the indoor temperature changes relatively quickly in a room with a small load, it is difficult to maintain a constant indoor temperature reaching the desired temperature, and there is a problem that the stabilization time is relatively long.

In addition, during heating operation, the control of the air conditioner that does not reflect the load release speed may cause the indoor temperature to rise rapidly beyond the desired temperature, and at this time, the operation of the indoor unit is turned off to decrease the indoor temperature (Thermo OFF. ) Phenomenon may occur.

If the operation of the indoor unit is turned off, the indoor temperature, which is far from the desired temperature, may be rapidly lowered, but again, the indoor temperature falls below the desired temperature, and there is a problem that heat loss and power loss occur when restarting. , There is a problem in that it is difficult to keep the indoor temperature desired by the user constant.

In addition, there is a problem in that it is difficult to quickly improve indoor comfort because the indoor temperature changes relatively slowly in a room with a large load.

Related to this, prior art literature information is as follows.

KR 10-2005-0075099 A KR 10-2005-0075096 A KR 10-2005-0117078 A KR 10-2005-0043123 A

It is an object of the present invention to provide an air conditioner and a control method for solving the above-described problem.

In addition, an object of the present invention is to provide an air conditioner and a control method thereof reflecting the load dissolution speed of each room in real time after initial driving.

In addition, an object of the present invention is to provide an air conditioner and a method for controlling the same in which the indoor temperature can be quickly stabilized to a user's desired temperature.

In addition, an object of the present invention is to provide an air conditioner capable of adjusting the amount of refrigerant introduced into an indoor unit according to a load-releasing speed, and a control method thereof.

In addition, an object of the present invention is to provide an air conditioner and a control method for adjusting the opening degree of an indoor expansion valve by reflecting a load release speed that varies according to the load size of each room.

In order to achieve the above object, the control method of an air conditioner according to an embodiment of the present invention is an air conditioner in which a plurality of indoor units installed in each room are connected to one outdoor unit, the user's desired temperature and the user's desire. Acquiring a set temperature difference defined as a difference between the actual indoor temperature of the room in which the temperature is input; Obtaining a virtual opening degree increment as a variable with a rate of change of the set temperature difference, which is defined as a degree that the obtained set temperature difference varies with time; And changing the opening degree of the indoor expansion valve of the corresponding room based on the obtained virtual opening degree increment.

In addition, the method may further include obtaining a final opening degree increment calculated as a value obtained by multiplying the obtained virtual opening degree increment by the pulse ratio of the corresponding yarn.

In addition, the indoor expansion valve of the corresponding room is characterized in that the opening degree is changed by the increment of the final opening degree.

In addition, the pulse ratio is defined as a ratio of a pulse value of an indoor expansion valve of the corresponding room and a total pulse value of an indoor expansion valve provided in all indoor units.

In addition, the virtual opening degree increment is a weight ratio value (λ) X first proportional constant (Kp) X (change rate of the set temperature difference + second ratio constant (Ki) X (control period/60) X the set temperature difference It is characterized in that it is calculated by an equation prescribed by ).

In addition, the control method of the air conditioner may further include determining whether the acquired virtual opening degree increment satisfies a preset range condition.

In addition, when the acquired virtual opening degree increment satisfies the preset range condition, the step of obtaining the most dynamic opening degree increment is performed.

In addition, the range condition is characterized in that -0.1 or more and +0.1 or less.

In addition, the control method of the air conditioner may include determining whether the obtained set temperature difference is less than or equal to a reference value; And stopping superheat distribution control for adjusting an opening degree of the indoor expansion valve through a temperature difference of the refrigerant flowing through the indoor heat exchanger when the obtained set temperature difference is less than the reference value.

In addition, the reference value is characterized in that it is set to 1 (°C).

In addition, the control method of the air conditioner may further include an initial driving step of determining an initial refrigerant distribution amount by calculating the initial load of each chamber, and introducing a refrigerant into each chamber according to the determined initial refrigerant distribution amount. have.

In addition, the initial load of each room is determined based on at least one of the capacity of the indoor unit, the indoor temperature, the difference between the indoor temperature and the user's desired temperature, the outdoor temperature, the area of the indoor thermal bridge, and the air volume of the indoor fan. To do.

In addition, the initial driving step may further include controlling an opening degree of an indoor expansion valve provided in an indoor unit installed in each room with a pulse ratio determined according to the initial load.

In another aspect, the air conditioner according to the embodiment of the present invention is an air conditioner in which a plurality of indoor units installed in each room are connected to one outdoor unit, and are disposed between the outdoor unit and the plurality of indoor units, and the plurality of A distributor connected to distribute the refrigerant to each of the indoor units of the unit; An indoor expansion valve provided in each of the indoor units to control an amount of refrigerant introduced into each of the indoor units; A temperature sensing unit for sensing the indoor temperature of each room; An input unit provided for each of the rooms to input a user's desired temperature; And a control unit for calculating a set temperature difference defined as a difference between the user's desired temperature and the indoor temperature, and a rate of change of the set temperature difference defined such that the set temperature difference varies with time.

In addition, the control unit may vary the opening degree of the indoor expansion valve by using an opening degree increment calculated based on a change rate of the set temperature difference.

In addition, the opening degree increment may be a virtual opening degree increment calculated as a variable of the set temperature difference and the change rate of the set temperature difference; And a final opening degree increment calculated by multiplying the virtual opening degree increment by a pulse ratio reflecting the load of each room.

In addition, the control unit may control the opening of the indoor expansion valve with a pulse value to which the final opening increment is applied.

In addition, the controller may individually control an opening degree of an indoor expansion valve provided in each of the indoor units.

In addition, a memory for storing information for calculating the opening degree increment may be further included.

According to the present invention, there is an advantage that the load can be relieved more quickly in a room with a large load, and in a room with a small load, the temperature difference between the user's desired temperature and the temperature becomes too large to prevent the indoor unit from turning off (Thermo OFF). There is an advantage that the indoor temperature is properly maintained according to the user's desired temperature.

In addition, it is possible to quickly create a comfortable air conditioning environment indoors, and there is an advantage in that the temperature desired by the user can be maintained relatively without deviation.

In addition, since the increment of the opening of the indoor expansion valve can be determined as a change rate of the set temperature difference as a variable, it is possible to adjust the opening of the indoor expansion valve according to the load release speed in real time. That is, there is an advantage of being able to determine how quickly the load of each room is relieved.

In addition, there is an advantage in that a more active and effective refrigerant distribution is performed to quickly release the load of each room and to meet the user's desired temperature.

In addition, since the increment of the opening degree of the indoor expansion valve is finally corrected at the ratio defined by the current pulse of the controlled indoor expansion valve to the total pulse, the load of each chamber determined in the initial operation can be adjusted by various factors (capacity, heat exchanger area, Air volume, indoor temperature, outdoor temperature, etc.) can be applied in a comprehensive manner, so it is possible to improve versatility for variables of load in each room.

In addition, since the increment of the opening degree of the indoor expansion valve is determined to correspond to the ratio of the load of each chamber, various factors determining the load of each chamber are considered, and thus there is an advantage in that more appropriate refrigerant distribution can be performed. Accordingly, it is possible to improve the heating efficiency of the air conditioner.

1 is a view showing the configuration of an air conditioner according to an embodiment of the present invention
2 is a block diagram showing the configuration of an air conditioner according to an embodiment of the present invention
3 is a flow chart showing a control method of an air conditioner according to an embodiment of the present invention
4 is an experimental diagram showing a temperature change in a room in a heating operation of an air conditioner according to an embodiment of the present invention
5 is an experimental diagram showing a change in indoor temperature in a cooling operation of an air conditioner according to an embodiment of the present invention

Hereinafter, exemplary embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but identical or similar elements are denoted by the same reference numerals regardless of reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used interchangeably in consideration of only the ease of preparation of the specification, and do not have meanings or roles that are distinguished from each other by themselves. In addition, in describing the embodiments disclosed in the present specification, when it is determined that a detailed description of related known technologies may obscure the subject matter of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are for easy understanding of the embodiments disclosed in the present specification, and the technical idea disclosed in the present specification is not limited by the accompanying drawings, and all modifications included in the spirit and scope of the present invention It should be understood to include equivalents or substitutes.

1 is a view showing the configuration of an air conditioner according to an embodiment of the present invention.

The air conditioner 1 according to an embodiment of the present invention may be a multi-air conditioner of simultaneous cooling and heating.

That is, in the air conditioner 1, a plurality of indoor units B1, B2, B3, B4 are connected to one outdoor unit A, and each indoor unit B1, B2, B3, B4 is each air conditioning space It can be configured to be installed on. At this time, each of the indoor units B1, B2, B3, and B4 is operated in any one of heating and cooling operation modes to condition the indoor air.

Referring to FIG. 1, the air conditioner 1 may include an outdoor unit A, a plurality of indoor units B1, B2, B3, and B4, and a distributor C.

For example, the plurality of indoor units B1, B2, B3, and B4 may include a first indoor unit B1, a second indoor unit B2, a third indoor unit B3, and a fourth indoor unit B4. .

The outdoor unit A may include compressors 53 and 54, an outdoor heat exchanger 51, an outdoor heat exchanger fan 61, and a four-way valve 62.

In addition, the outdoor unit A may further include a receiver 50. The receiver 50 selectively introduces and temporarily stores the refrigerant flowing through the liquid pipe 72, so that the amount of refrigerant circulated in the air conditioner 1 can be adjusted.

The outdoor unit A may further include an accumulator 52. The accumulator 52 may separate a gaseous refrigerant from a liquid and gaseous mixed refrigerant and supply it to the compressors 53 and 54.

The suction units of the compressors 53 and 54 may be connected to the accumulator 52. That is, the gaseous refrigerant discharged from the accumulator 52 may be sucked into the first and second compressors 53 and 54.

The compressors 53 and 54 may compress and discharge the sucked refrigerant. For example, the first compressor 53 may be an inverter compressor capable of varying the compression capacity of the refrigerant, and the second compressor 54 may be a constant speed compressor having a constant compression capacity of the refrigerant.

Discharge pipes 55 and 56 are connected to the discharge portions of the compressors 53 and 54. The discharge pipes 55 and 56 may include a first discharge pipe 55 connected to the first compressor 53 and a second discharge pipe 56 connected to the second compressor 54.

The first discharge pipe 55 and the second discharge pipe 56 are provided so as to be laminated by the joining portion 57. That is, the high-temperature and high-pressure gaseous refrigerant compressed by each of the compressors 53 and 54 may be laminated in the bonding unit 57 through the discharge pipes 55 and 56.

Oil separators 58 and 59 are installed in the discharge pipes 55 and 56, respectively. The oil separator (58,59) is a first oil separator (58) for separating oil from refrigerant discharged from the first compressor (53) and a first oil separator (58) for separating oil from refrigerant discharged from the second compressor (54). 2 It may include an oil separator (59).

In the first and second oil separators (58, 59), a first oil return pipe (30) and a second oil return pipe (31) for guiding the separated oil to the suction portions of the compressors (53, 54), respectively. Connected to this.

Meanwhile, a high-pressure gas pipe 63 for bypassing the refrigerant discharged from the compressors 53 and 54 without passing through the four-way valve 62 may be connected to the bonding unit 57.

In addition, the bonding part 57 may be connected to a third discharge pipe 68 extending to the four-way valve 62.

The four-way valve 62 may determine a flow path of the high-temperature and high-pressure gaseous refrigerant laminated by the bonding unit 57. As an example, the four-way valve 62 may change a flow path of the gaseous refrigerant or branch and flow the gaseous refrigerant, depending on whether the cooling main operation or the heating main operation is performed.

The outdoor heat exchanger 51 is connected to the four-way valve 62 by a first connection pipe 71. The outdoor heat exchanger 51 may condense or evaporate the refrigerant by exchanging heat with external air. During a cooling operation, the outdoor heat exchanger 51 may function as a condenser, and during a heating operation, the outdoor heat exchanger 51 may function as an evaporator.

Meanwhile, the outdoor unit fan 61 may be installed to facilitate heat exchange between the outdoor heat exchanger 51. In addition, the outdoor unit fan 61 may introduce external air into the outdoor heat exchanger 51.

The outdoor unit A may further include an outdoor expansion valve 65 and a supercooling device 66. In detail, the outdoor expansion valve 65 and the supercooling device 66 may be installed on a liquid pipe 72 connecting the outdoor heat exchanger 51 and the distributor C, respectively.

The outdoor expansion valve 65 may be provided as an electronic expansion valve (EEV). The outdoor expansion valve 65 may perform a function of expanding a refrigerant during a heating operation. Specifically, the outdoor expansion valve 65 may perform a function of expanding the refrigerant condensed in each of the indoor heat exchangers 11, 21, 31, and 41 before flowing into the outdoor heat exchanger 51. To this end, the opening degree of the outdoor expansion valve 65 may be controlled.

During the cooling operation, the outdoor expansion valve 65 may not expand the refrigerant. For example, the outdoor expansion valve 65 may pass the refrigerant condensed in the outdoor heat exchanger 51 as it is without expanding it before flowing it into each of the indoor heat exchangers 11, 21, 31, and 41. At this time, the outdoor expansion valve 65 may be fully open.

The supercooling device 66 may overcool a part of the refrigerant that passes through the outdoor heat exchanger 51 and moves to the distributor C during the cooling operation. Meanwhile, the supercooling device 66 may include a recovery pipe 66d extending to the suction pipe 64.

The distributor (C) may be disposed between the outdoor unit (A) and a plurality of indoor units (B1, B2, B3, B4).

On the other hand, the distributor (C) is divided into a plurality of indoor units (B1, B2, B3, B4) according to the simultaneous operation of the cooling front room, the heating front room, the cooling subject and the heating subject, classified according to the operation mode of each indoor unit. It can be distributed to each indoor unit.

To this end, the distributor C may include a high-pressure gas header 81, a low-pressure gas header 82, a liquid header 83, and a plurality of valves (not shown).

The high-pressure gas header 81 may be connected to a high-pressure gas pipe 63 connected to the bonding unit 57 and to each of the indoor heat exchangers 11, 21, 31, and 41.

In addition, the low pressure gas header 82 may be connected to the low pressure gas pipe 75 connected to the suction pipe 64 and to each of the indoor heat exchangers 11, 21, 31, and 41.

In addition, the liquid header 83 may be connected to the liquid pipe 72 connected to the subcooling device 66 and to each of the indoor heat exchangers 11, 21, 31, and 41, respectively.

Meanwhile, the plurality of indoor units B1, B2, B3, and B4 may include a first indoor unit B1, a second indoor unit B2, a third indoor unit B3, and a fourth indoor unit B4.

Each of the first to fourth indoor units B1, B2, B3, and B4 may perform a cooling or heating operation.

The first indoor unit B1 may include a first indoor heat exchanger 11, a first indoor expansion valve 12, and a first indoor fan 15.

In addition, a first indoor heat exchanger connection pipe 13 may be connected to one end of the first indoor heat exchanger 11, and a second indoor heat exchanger connection pipe 14 may be connected to the other end.

The first indoor expansion valve 12 may include an electronic expansion valve (EEV). For example, the first indoor expansion valve 12 may be installed on the first indoor heat exchanger connection pipe 13.

In addition, the first indoor expansion valve 12 may adjust the amount of refrigerant flowing through the first indoor heat exchanger 11 through opening degree control. For example, the controller 200 to be described later may independently control the opening degree of the first indoor expansion valve 12 provided in the first indoor unit B1.

That is, the air conditioner 1 individually controls the operation of the indoor units B1, B2, B3, B4 in each room according to the user's desired temperature in each room, thereby managing the indoor temperature of each room. have.

On the other hand, the second to fourth indoor units (B2, B3, B4), respectively, indoor heat exchangers (21, 31, 41), indoor expansion valves (22, 32, 42) and indoor fans (25, 35, 45). ) Can be included. In detail, the second indoor unit B2 may include a second indoor heat exchanger 21, a second indoor expansion valve 22, and a second indoor fan 25. The third indoor unit B3 may include a third indoor heat exchanger 31, a third indoor expansion valve 32, and a third indoor fan 35. The fourth indoor unit B4 may include a fourth indoor heat exchanger 41, a fourth indoor expansion valve 42, and a fourth indoor fan 45.

Here, each heat exchanger (21, 31, 41), indoor expansion valves (22, 32, 42) and indoor fans (25, 35, 45) constituting the second to fourth indoor units (B2, B3, B4) For the description of ), the description of the configuration of the first indoor unit B1 is used.

A first indoor expansion valve 12 provided in the first indoor unit B1, a second indoor expansion valve 22 provided in the second indoor unit B2, and a third indoor unit provided in the third indoor unit B3 The expansion valve 32 and the fourth indoor expansion valve 42 provided in the fourth indoor unit B4 may adjust the amount of refrigerant flowing into each indoor unit by controlling the opening degree.

During the heating operation, the first indoor heat exchanger connection pipes 13, 23, 33, 43 connected to the first to fourth indoor units B1, B2, B3, and B4 are provided with the first to fourth indoor heat exchangers 11, The liquid refrigerant condensed in 21, 31, 41 may be guided to the liquid header 83 of the distributor C.

In this case, the second indoor heat exchanger connection pipes 14, 24, 34, 44 connected to the first to fourth indoor units B1, B2, B3, and B4 that are operated by heating, distribute the high-pressure gaseous refrigerant to the distributor C ) From the high-pressure gas header 81 to the first to fourth indoor heat exchangers 11, 21, 31, 41.

The indoor heat exchanger (11, 21, 31, 41) may condense or evaporate a refrigerant by exchanging heat with indoor air. In order to facilitate heat exchange performed in the indoor heat exchanger (11, 21, 31, 41), the indoor unit fan (15, 25, 35, 45) is installed around the indoor heat exchanger (11, 21, 31, 41) Can be.

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

Referring to FIG. 2, the air conditioner 1 includes a control unit 100, a memory 150 for storing information, a temperature sensing unit 200 for sensing temperature, and an input unit 300 for receiving a user's desired temperature. ) May be further included.

The controller 100 may include a central controller 110 for controlling the outdoor unit A and a distribution controller 120 for controlling a plurality of indoor units B1, B2, B3, and B4.

The central controller 110 may control the opening degree of the outdoor expansion valve 65. In addition, the central controller 110 may control the total amount of refrigerant discharged from the compressors 53 and 54 and circulating through the entire cycle.

The distribution controller 120 may control distribution of the refrigerant so that an appropriate amount of the refrigerant can be provided to each of the indoor units B1, B2, B3, and B4 installed in each room. For example, the distribution controller 120 may individually control the opening degrees of the indoor expansion valves 12, 22, 32, and 42 installed in each indoor unit. Accordingly, the distribution controller 120 may adjust the flow and amount of the refrigerant so that the refrigerant is distributed in an appropriate amount according to the load condition of the indoor unit in each room.

Various types of information for operating the air conditioner 1 may be stored in the memory 150. For example, the memory 150 includes the capacity of each indoor unit (B1, B2, B3, B4), the area of the indoor heat exchanger (11, 21, 31, 41), and the indoor fans (15, 25, 35, 45). Information about the air volume, etc. can be stored.

The temperature sensing unit 200 may detect a temperature of a fluid or an object surface using a detection element, convert the detected temperature into an electric signal, and transmit the detected temperature to the controller 100. Here, the detection element may include a thermistor, platinum, nickel, thermocouple, or the like.

In addition, the temperature sensing unit 200 may include a plurality of temperature sensors to detect the refrigerant flowing through each pipe, the outdoor temperature, the indoor temperature of each room, and the inlet and outlet temperatures of the indoor heat exchanger. .

For example, the temperature sensing unit 200 may include a temperature sensor installed in a refrigerant pipe provided at an inlet and an outlet of the indoor heat exchanger 11, 21, 31, and 41, respectively. Accordingly, since the temperature sensing unit 200 can detect the temperature of the refrigerant passing through the indoor heat exchanger, it is possible to detect an overheating degree or a subcooling degree of the cold degree. In detail, the control unit 200 is based on the inlet temperature and the outlet temperature of the indoor heat exchanger (11, 21, 31, 41) sensed by the temperature sensing unit 200, the indoor heat exchanger (11, 21, 31, 41) The degree of supercooling or superheating of can be calculated.

In addition, the temperature sensing unit 200 may include a temperature sensor that senses the current indoor temperature of each room. Accordingly, the temperature sensing unit 200 may sense the current temperature of each room and transmit it to the control unit 100.

In addition, the temperature sensing unit 200 may include a temperature sensor installed at the inlet and outlet of the compressors 53 and 54. As an example. The temperature sensing unit 200 may detect the inlet temperature and the outlet temperature of the compressors 53 and 54. Accordingly, the control unit 100 may calculate the degree of superheat of the compressor 240 based on the inlet temperature and the outlet temperature of the compressor 220 sensed by the temperature sensing unit 200.

The input unit 300 may be installed in each room to individually receive a user's desired temperature existing in each room. Further, the input unit 300 installed in each room may transmit a desired temperature set by a user of each room to the control unit 100.

Accordingly, the controller 100 may control the operation of the indoor unit in each room so that the indoor temperature of each room is maintained at the desired temperature.

3 is a flow chart showing a control method of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 3, the air conditioner 1 may perform an initial driving step (S10).

The initial driving step (S10) may be understood as a step of calculating an initial load of each chamber to determine an initial refrigerant distribution amount, and introducing it to each indoor unit.

In the initial driving step (S10), the indoor unit of the room may start to operate according to the desired temperature input by the user of each room. For example, the user may input a desired temperature through the input unit 300. The input desired temperature may be provided to the controller 100. In this case, the control unit 100 may receive the indoor temperature of the room in which the desired temperature is input together with the input desired temperature, and the indoor unit capacity of the room, the air volume of the indoor fan, and the room Information on the area of the heat exchanger and the like can be provided.

In addition, the controller 100 may operate an indoor unit of a corresponding room to which the desired temperature is input in order to adjust the indoor temperature to the desired temperature.

In the initial driving step (S10), the control unit 100 may adjust an initial amount of refrigerant so that an appropriate refrigerant can be introduced into the indoor unit of the corresponding room. For example, after calculating the initial load of each room, the controller 100 may calculate the total total load of the air conditioner 1 by summing them. In addition, the controller 100 controls the compressors 53 and 54 to correspond to the total load, thereby discharging the entire refrigerant required by the air conditioner 1.

Here, the initial load of each room is set as a basic load based on the capacity of the indoor units B1, B2, B3, B4 installed in each room, and then the room temperature of each room, A correction value using information such as the difference between the indoor temperature and the desired temperature and the outdoor temperature may be applied to the basic load to be calculated.

For example, assuming an air conditioner 1 equipped with two indoor units B1 and B2 having a capacity of 8K of the first indoor unit B1 and 12K of the second indoor unit B2 is assumed, the controller 100 ) Is to set the basic load of the first room where the first indoor unit (B1) is installed to the capacity ratio of 8/20, and the basic load of the second room where the second indoor unit (B2) is installed to the capacity ratio of 12/20. I can.

And as described above, the control unit 100 may calculate the final ratio by applying the correction value to the capacity ratio of each room. And the final ratio may be defined as the initial load of each room. Here, since the technique of applying the correction value to the basic load is described in the aforementioned prior art document, it will be omitted in the detailed description of the present invention.

The controller 100 may determine a pulse ratio for determining the opening degree of the indoor expansion valves 12 and 22 according to the initial load of each chamber.

For example, when two indoor units B1 and B2 are provided, the controller 100 sets the pulse ratio of the first indoor expansion valve 12 to 8/20 if the initial load of the first chamber is 8/20. You can decide. In addition, if the initial load of the second chamber is 12/20, the controller 100 may determine the pulse ratio of the second indoor expansion valve 22 as 12/20.

Therefore, 8/20 of the total refrigerant discharged from the compressors 53 and 54 is introduced into the first indoor unit B1 by the indoor expansion valves 12 and 22 opened according to the pulse ratio, and the remaining 12/ 20 may be introduced as the second indoor unit B2.

On the other hand, a user existing in each room can feel improved indoor comfort when the indoor temperature is rapidly reached and maintained at the input desired temperature. In other words, in a room with a relatively large load, the load dissolving speed should be faster, and in a room with a relatively small load, the load dissolving speed is too fast to prevent the indoor unit from turning off (Thermo Off). It must be able to maintain the temperature.

Meanwhile, the load of each room reflected in the initial driving step S10 may be changed by various variables. In addition, since the actual load of each room may change over time, there may be a difference from the load calculated by the conventional method.

In addition, in order to minimize the difference from the actual load of each room, it is very difficult to find all the variables that can determine the actual load during operation of the indoor unit and calculate them to be reflected in control.

In addition, in order to minimize the difference from the actual load of each room, if only the difference between the desired temperature entered by the user and the actual indoor temperature (hereinafter, set temperature difference) is used as a variable, the indoor temperature of each room that changes in real time There is a problem that is difficult to respond quickly. In addition, since the change in the indoor temperature is also changed according to the actual load size of each room, there is a problem in that it is difficult to efficiently control the indoor unit, which must be kept constant by reaching the user's desired temperature.

For example, assuming that the actual indoor load is relatively small, since the load is relieved at a high speed after initial driving, the indoor temperature can quickly reach the user's desired temperature.

However, conventional air conditioners cannot predict in advance when the indoor temperature reaches the user's desired temperature, and the amount of refrigerant introduced into the indoor unit is determined whether the result of the set temperature difference has a negative (-) or positive (+) sign. Because of the control, there is a problem that the time required to keep the user's desired temperature constant within a predetermined deviation (hereinafter, stabilization time) becomes relatively long.

In addition, since the conventional air conditioner has a slow control corresponding to the change in the indoor temperature, there may be a case where the indoor temperature changes rapidly and greatly deviates from the user's desired temperature. For example, during heating operation, when the desired temperature is greatly exceeded due to a rapid increase in the indoor temperature of the conventional air conditioner, the indoor unit may be turned off (Thermo OFF) to rapidly lower the indoor temperature again. However, in this case, since the indoor unit must be operated again, unnecessary power consumption is caused, and inefficient operation is performed.

In order to solve the above-described problem, the air conditioner 1 according to the embodiment of the present invention may obtain a difference in set temperature of a corresponding room into which a desired temperature is input after the initial driving step S10 (S20).

Here, the set temperature difference may be defined as a difference between the desired temperature input by the user and the actual indoor temperature of the room. The indoor temperature of the corresponding room may be detected by the temperature sensing unit 200.

As an example, the control unit 100 may receive information on the room temperature of the corresponding room from the temperature sensing unit 200 and calculate a difference value from the desired temperature provided from the input unit 300 of the corresponding room.

The control unit 100 detects a difference in set temperature for each room, and can control by individually applying the steps described below to the indoor expansion valves 12, 22, 32, and 42 of each room.

The air conditioner 1 may determine whether the obtained set temperature difference is less than or equal to a reference value S. (S25)

As an example, the control unit 100 may determine whether the obtained set temperature difference is equal to or less than a preset reference value S.

Here, the reference value S may be understood as a criterion indicating whether the indoor temperature of the corresponding room has reached a user's desired temperature. For example, the reference value S may be set to 1 (°C).

When the obtained set temperature difference is less than or equal to the reference value S, the air conditioner 1 may stop the superheat distribution control for the indoor unit of the corresponding room (S30).

The superheat distribution control can be understood as a control for improving the performance and heat exchange efficiency of the air conditioner 1 by adjusting the refrigerant temperature flowing into the outdoor unit A to a certain level, and protecting the outdoor unit A. . For example, the superheat distribution control is based on the superheat degree defined by the difference between the discharge temperature and the inlet temperature of the refrigerant flowing through the indoor heat exchanger (11, 21, 31, 41). The indoor expansion valves 12, 22, 32, and 42 may be controlled so that the distribution amount of refrigerant introduced into the indoor units B1, B2, B3, and B4 is adjusted.

The superheat distribution control may be separately performed by following a parallel control process in the initial driving step (S10).

If the obtained set temperature difference is less than or equal to the reference value S, it can be understood that the room temperature of the corresponding room has reached the user's desired temperature. At this time, in order to maintain the indoor temperature of the room at the user's desired temperature, the control unit 100 must precisely control the distribution amount of refrigerant introduced into each indoor unit.

That is, if the control process of other indoor expansion valves is performed together in a section in which the set temperature difference has a small value, accurate and precise indoor temperature management may become difficult.

Therefore, when the superheat distribution control performed in parallel is stopped, the opening degree control of the indoor expansion valves 12, 22, 32, 42 is a control capable of quickly stabilizing the indoor temperature so that it matches the user's desired temperature. Can be done.

Accordingly, an optimal indoor expansion valves 12, 22, 32, and 42 control environment for stabilizing the indoor temperature may be provided. That is, the control unit 100 may intensively control the opening degree of the indoor expansion valves 12, 22, 32, and 42 so that the indoor temperature is kept constant at the user's desired temperature.

Consequently, there is an advantage in that the room temperature is controlled more precisely and accurately, so that the stabilization time can be shortened and the desired temperature of the user can be kept constant at an early time.

In addition, the air conditioner 1 may acquire a virtual opening increment of the indoor expansion valves 12, 22, 32, 42 (S40).

For example, when the superheat distribution control is stopped or the set temperature difference exceeds a reference value (S), the control unit 100 is configured to control the opening degree of the indoor expansion valve (12, 22, 32, 42). Dogs can also acquire increments.

Meanwhile, when the set temperature difference exceeds the reference value S, the virtual opening degree increment may be larger than when the superheat distribution control is stopped for faster load relief.

The controller 100 may update information on the set temperature difference in real time. In addition, the control unit 100 may detect a change in the set temperature difference over time and calculate a change rate of the set temperature difference. For example, the rate of change of the set temperature difference may be provided as an average rate of change over a predetermined time interval or an instantaneous rate of change at any one time in a function of the set temperature difference and time.

That is, the rate of change of the set temperature difference is defined as representing the degree to which the set temperature difference changes over time as a ratio.

In a room having a relatively small load, the rate of change of the set temperature difference will be detected as a value larger than that of a room having a relatively large load. Accordingly, the control unit 100 may determine a load release speed of a corresponding room to which the user's desired temperature is input by sensing a rate of change of the set temperature difference. As a result, the rate of change of the set temperature difference can be understood as a measure for determining how quickly the load of the corresponding room is relieved.

The virtual opening degree increment (Δv) may be calculated by Equation 1 using a rate of change of the set temperature difference and the set temperature difference as variables.

In Equation 1, λ is a weight ratio value, Kp is a proportional constant for proportional operation (P operation), Ki is a proportional constant for integral operation (I operation), and the control period is a preset time (unit, sec). For example, the control period may be set to 60 (sec).

Data on λ, Kp, Ki, and control period related to Equation 1 may be previously stored in the memory 150.

That is, the control unit 100 may obtain the virtual opening degree increment Δv using the calculated change rate of the set temperature difference and the set temperature difference. The virtual opening degree increment may be obtained as a ratio value. For example, the virtual opening degree increment may be expressed as a percentage.

In addition, the air conditioner 1 may determine whether the acquired virtual opening degree increment satisfies a preset range condition (S50).

Here, the range condition is defined as a lower limit value and an upper limit value of an allowable opening degree increment of the indoor expansion valve (12, 22, 32, 42).

If the increment for changing the opening degree of the indoor expansion valves 12, 22, 32, 42 exceeds an appropriate range, indoor air conditioning efficiency may decrease due to a sudden change in the amount of refrigerant introduced into the indoor unit, and unnecessary energy Can be wasted.

Accordingly, the air conditioner 1 can control the indoor expansion valves 12, 22, 32, and 42 to adjust the opening degrees after confirming whether the virtual opening degree increment obtained in the previous step satisfies an appropriate range.

The range condition may be set for each room and stored in advance in the memory 150. Since the load of each room is different from each other, the lower limit value and the upper limit value of the opening degree increment may be different respectively, and thus the range condition may also be set for each room.

That is, the controller 100 may determine whether the acquired virtual opening degree increment Δv satisfies a condition equal to or greater than a lower limit value of the virtual opening degree increment and less than the upper limit value of the virtual opening degree increment. For example, the range condition may be set as -0.1≦virtual opening degree increment (Δv)≦+0.1. In other words, the virtual opening degree increment should satisfy within ±10%.

On the other hand, since the virtual opening degree increment Δv is calculated as a change rate of the set temperature difference and the set temperature difference as variables, if the change rate of the set temperature difference and the set temperature difference are the same for each room, there is a problem of having the same virtual opening degree increment value .

In detail, when the capacity of the indoor unit installed in each room, the area of the indoor heat exchanger, the air volume of the indoor fan, etc. are different, the opening degree of the indoor expansion valves 12, 22, 32, 42 of each room with the same virtual opening increment value If the same change is made, inadequate refrigerant distribution may be achieved in which the indoor load (indoor capacity, area of the indoor heat exchanger, air volume of the indoor fan, etc.) of each room described above is not considered.

For example, when the indoor unit B1 of the first chamber having a relatively large capacity and the indoor unit B2 of the second chamber having a relatively small capacity are provided, the first indoor expansion valve 12 and the second indoor unit Although the expansion valve 22 is adjusted in the opening degree to reflect the same virtual opening increment (for example, 5% reduction), the amount of refrigerant required by each indoor unit is different depending on the indoor load such as capacity. The performance will appear differently. That is, the first indoor unit B1 may suffer from a phenomenon in which the amount of refrigerant is rapidly shortened, while the second indoor unit B2 may still have a problem in which the amount of refrigerant is still excessively supplied.

To solve this, the air conditioner 1 may obtain a final opening degree increment based on the virtual opening degree increment (S60)

In detail, when the virtual opening degree increment satisfies the range condition, the controller 100 may calculate a final opening degree increment Δr based on the virtual opening degree increment Δv.

Here, the final opening degree increment Δr is a ratio value finally applied to adjust the opening degree of the indoor expansion valve provided in the corresponding room in which the user's desired temperature is input.

The final opening degree increment Δr may be calculated according to Equation 2 below.

That is, the final opening degree increment Δr may be calculated as a value obtained by multiplying the acquired virtual opening degree increment Δv by the pulse ratio of the corresponding yarn.

Here, the pulse ratio of the corresponding chamber may be defined as a ratio of the pulse value of the indoor expansion valve of the corresponding chamber and the total pulse value of the total indoor expansion valves 12, 22, 32, and 42. That is, the pulse ratio of the corresponding yarn can be understood as a pulse ratio calculated according to the initial load in the above-described initial driving step S10.

Accordingly, the air conditioner 1 can provide an amount of refrigerant suitable for the load of each room even when the opening degree of the indoor expansion valve is changed.

In addition, the air conditioner 1 may finally adjust the opening degree of the indoor expansion valve of the corresponding chamber based on the obtained final opening degree increment Δv (S70).

In detail, the controller 100 may calculate variable pulse values of the indoor expansion valves 12, 22, 32, and 42 by multiplying the pulse value of the indoor expansion valve of the corresponding room by the final opening degree increment Δv. In addition, the control unit 100 may adjust the opening degree of the indoor expansion valve of the corresponding chamber through the variable pulse value.

That is, the opening degree of the indoor expansion valve of the corresponding room may be changed according to the calculated variable pulse value.

In addition, the air conditioner 1 may return to step S20 in real time or according to a preset control period and repeat the above-described steps.

As a result, the rate of change of the set temperature difference updated by the control unit 100 may gradually have a small value.

Accordingly, the control unit 100 controls the opening degree of the indoor expansion valves 12, 22, 32, 42 of the corresponding room to change based on the change rate of the set temperature difference, An amount of refrigerant capable of maintaining a constant temperature may be provided to the indoor unit of the corresponding chamber.

Accordingly, in the air conditioner 1 according to the embodiment of the present invention, the indoor temperature does not converge to the user's desired temperature, and the hunting phenomenon repeatedly exceeds and falls based on the desired temperature can be eliminated or minimized. . Thus, there is an advantage of relatively shortening the stabilization time.

4 is an experimental diagram showing a temperature change in a room in a heating operation of an air conditioner according to an embodiment of the present invention. In detail, FIG. 4 is a change in room temperature over time of an air conditioner 1 according to an embodiment of the present invention using a rate of change of a set temperature difference in a heating operation and a conventional air conditioner without using a rate of change of the set temperature difference. It is a graph comparing.

Referring to FIG. 4, the thin one-dot chain line shows the temperature change of the conventional air conditioner in one room with a relatively small load, and the thin solid line shows the temperature change of the conventional air conditioner in the two rooms with a relatively large load. Show

In addition, the thick solid line shows the temperature change of the air conditioner 1 of the present invention in the same room 1 room, and the thick dotted line shows the temperature change of the air conditioner 1 of the present invention in the same room 2 rooms.

In addition, in the experiment of FIG. 4, the user's desired temperature for one room and two rooms is set to 28 (°C).

In the graph of FIG. 4, it can be seen that one room with a small load in common reaches the user's desired temperature faster than two rooms with a large load.

And, as described above, the conventional air conditioner turns off the indoor unit for rapidly lowering the indoor temperature as it reaches a temperature relatively higher than the user's desired temperature after reaching the user's desired temperature in one indoor room and two indoor rooms. (Thermo Off) occurs at the time points TF1 and TF2, respectively.

However, the air conditioner 1 of the present invention does not cause the indoor unit to be turned off (Thermo Off), maintains the indoor temperature within a relatively small deviation from the user's desired temperature, and is gentle from the vicinity of the user's desired temperature. It can be seen that the indoor temperature of each room is adjusted to the user's desired temperature as the temperature changes with one slope.

In addition, it can be seen that the air conditioner 1 of the present invention stably maintains the indoor temperature reaching the user's desired temperature faster than the conventional air conditioner.

In detail, it can be seen that in the air conditioner 1 of the present invention, the stabilization time of one indoor room is about 30 minutes, and the stabilization time of two indoor rooms is about 40 minutes.

However, in the conventional air conditioner, it can be confirmed that the stabilization time takes 1 hour or more because the indoor temperature varies significantly from the user's desired temperature.

In addition, in the air conditioner 1 of the present invention, the indoor temperature does not converge to the user's desired temperature, and the hunting phenomenon that repeatedly exceeds and falls based on the desired temperature hardly appears. It can be confirmed that the hunting phenomenon is continuously occurring.

5 is an experimental diagram showing a temperature change in a room in a cooling operation of an air conditioner according to an embodiment of the present invention. In detail, FIG. 5 is a change in room temperature over time of an air conditioner 1 according to an embodiment of the present invention using a rate of change of the set temperature difference in cooling operation and a conventional air conditioner without using a rate of change of the set temperature difference. It is a graph comparing.

In the experiment of FIG. 5, the user's desired temperature is set to 26 (°C).

Referring to FIG. 5, when the conventional air conditioner reaches the user's desired temperature during cooling operation, the indoor unit is turned off (Thermo Off) for rapidly increasing the indoor temperature as it reaches a temperature relatively lower than the user's desired temperature. It can be seen that it occurs at the time points TF1 and TF2, respectively.

However, it can be seen that the air conditioner 1 of the present invention maintains the indoor temperature within a relatively small deviation range from the user's desired temperature without the indoor unit being turned off (Thermo Off).

In addition, the air conditioner 1 of the present invention can confirm that the indoor temperature is adjusted to the user desired temperature while the temperature changes with a gentle slope from the vicinity of the user desired temperature.

In addition, it can be seen that the air conditioner 1 of the present invention stably maintains the indoor temperature reaching the user's desired temperature faster than the conventional air conditioner.

Accordingly, the conventional air conditioner has a relatively large deviation from the user's desired temperature and the indoor temperature changes, so that the stabilization time is longer than that of the air conditioner of the present invention.

In addition, the air conditioner 1 of the present invention confirms that the indoor temperature does not converge to the user's desired temperature, and the hunting phenomenon that repeatedly exceeds and falls based on the desired temperature is minimized compared to the case of the conventional air conditioner. I can.

As a result, according to the control method of the air conditioner 1 according to the embodiment of the present invention described above, it is possible to determine the increment of the opening degree of the indoor expansion valves 12, 22, 32, 42 using the change rate of the set temperature difference. Therefore, it is not necessary to search for various factors that form an actual load, and there is an advantage in that it is possible to quickly perform control corresponding to a change in indoor temperature.

In addition, since the amount of refrigerant introduced into the indoor units B1, B2, B3, B4 can be adjusted based on the rate of change of the set temperature difference, the indoor temperature does not converge to the user's desired temperature and is repeatedly based on the desired temperature. There is an advantage of eliminating or minimizing the hunting phenomenon that goes over and falls. That is, there is an advantage in that the stabilization time is shortened.

In addition, since the rate of change of the set temperature difference is used, there is an advantage of being able to predict in advance the time point at which the indoor temperature reaches the user's desired temperature. Therefore, since the amount of refrigerant introduced into the indoor units B1, B2, B3, B4 can be preemptively adjusted by adjusting the opening degree of the indoor expansion valves 12, 22, 32, 42, the indoor temperature is quickly adjusted to the user's desired temperature. There is an advantage that can be maintained as.

Meanwhile, the virtual opening degree increment and the final opening degree increment may be collectively referred to as “opening degree increment”.

1: air conditioner 12, 22, 32, 42: indoor expansion valve
100: control unit 200: temperature sensing unit

Claims (15)

In an air conditioner in which a plurality of indoor units installed in each room are connected to one outdoor unit,
Acquiring a set temperature difference defined as a difference between the user's desired temperature and the actual indoor temperature of the room into which the user's desired temperature is input;
Obtaining a virtual opening degree increment as a variable with a rate of change of the set temperature difference, which is defined as a degree that the obtained set temperature difference varies with time; And
And changing the opening degree of the indoor expansion valve of the corresponding room based on the acquired virtual opening degree increment,
The virtual opening degree increment is a weight ratio value (λ) X first proportional constant (Kp) X (change rate of the set temperature difference + second ratio constant (Ki) X (control period/60) X the set temperature difference) Air conditioner control method calculated by the prescribed formula.
The method of claim 1,
Further comprising the step of obtaining a final opening degree increment calculated as a value obtained by multiplying the acquired virtual opening degree increment by the pulse ratio of the corresponding yarn,
The indoor expansion valve of the corresponding chamber is a control method of an air conditioner in which the opening degree is changed by the increment of the final opening degree.
The method of claim 2,
The pulse ratio is defined as a ratio of a pulse value of an indoor expansion valve of the corresponding room and a total pulse value of indoor expansion valves provided in all indoor units.
delete The method of claim 2,
Further comprising the step of determining whether the acquired virtual opening degree increment satisfies a preset range condition,
When the acquired virtual opening degree increment satisfies the preset range condition, the control method of an air conditioner performing the step of obtaining the final opening degree increment.
The method of claim 5,
The above range conditions are -0.1 or more and +0.1 or less.
The method of claim 1,
Determining whether the obtained set temperature difference is less than or equal to a reference value; And
When the obtained set temperature difference is less than the reference value, the control of the air conditioner further comprising: stopping superheat distribution control for adjusting the opening degree of the indoor expansion valve through a temperature difference of the refrigerant flowing through the indoor heat exchanger Way.
The method of claim 7,
The control method of the air conditioner in which the reference value is set to 1 (°C).
The method of claim 1,
Further comprising an initial driving step of calculating an initial load of each chamber to determine an initial refrigerant distribution amount, and introducing a refrigerant into each chamber according to the determined initial refrigerant distribution amount,
The initial load of each room is determined based on at least one of the capacity of the indoor unit, the indoor temperature, the difference between the indoor temperature and the user's desired temperature, the outdoor temperature, the area of the indoor heat pump, and the air volume of the indoor fan. Control method.
The method of claim 9,
The initial driving step,
The control method of an air conditioner further comprising controlling an opening degree of an indoor expansion valve provided in an indoor unit installed in each room at a pulse ratio determined according to the initial load.
In an air conditioner in which a plurality of indoor units installed in each room are connected to one outdoor unit,
A distributor disposed between the outdoor unit and the plurality of indoor units and connected to distribute a refrigerant to each indoor unit of the plurality of indoor units;
An indoor expansion valve provided in each of the indoor units to control an amount of refrigerant introduced into each of the indoor units;
A temperature sensing unit for sensing the indoor temperature of each room;
An input unit provided for each room to input a user's desired temperature; And
And a control unit for calculating a change rate of a difference between a set temperature defined by a difference between the user's desired temperature and the indoor temperature, and a set temperature difference defined by a degree to which the set temperature difference varies with time,
The control unit,
The opening degree of the indoor expansion valve is varied using a virtual opening degree increment calculated based on the change rate of the set temperature difference,
The virtual opening degree increment is a weight ratio value (λ) X first proportional constant (Kp) X (change rate of the set temperature difference + second ratio constant (Ki) X (control period/60) X set temperature difference) Air conditioner calculated by the prescribed formula.
The method of claim 11,
The control unit,
A final opening degree increment calculated by multiplying the virtual opening degree increment by a pulse ratio reflecting the load of each room is obtained,
An air conditioner that controls the opening of the indoor expansion valve with a pulse value to which the final opening increment is applied.
delete The method of claim 11,
The control unit individually controls an opening degree of an indoor expansion valve provided in each of the indoor units.
delete

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