KR101995584B1 - Air-conditioning system and controlling method thereof - Google Patents

Abstract

The present invention relates to an air conditioning system and a control method thereof. A control method of an air conditioning system according to an embodiment of the present invention is a control method of an air conditioning system having a plurality of indoor units arranged in different spaces and a plurality of expansion valves provided corresponding to the plurality of indoor units, The target opening amount for operating the compressor through the indoor unit having the largest difference between the set temperatures and for the temperature of the refrigerant discharged from the compressor to correspond to the predetermined appropriate discharge temperature is calculated and stored in the indoor temperature and the set temperature information of each indoor unit Calculating an opening ratio of each expansion valve by dividing the expansion amount of each expansion valve by the sum of opening amounts, calculating the opening ratio of each expansion valve, multiplying the target opening amount by the opening ratio, The amount of opening is determined and a plurality of expansion valves are controlled accordingly.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an air conditioning system,

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

The air conditioning system is a system for keeping the air in a predetermined space in a most suitable state according to the purpose of use. Generally, the air conditioning system includes a compressor, a condenser, an expansion device, and an evaporator, and a refrigerant cycle for compressing, condensing, expanding, and evaporating the refrigerant is driven to cool or heat the predetermined space.

At this time, the predetermined space may be variously proposed according to the place where the air conditioning system is used. For example, when the air conditioning system is used in a home or an office, the predetermined space may be a house or an indoor space of a building. In addition, when the air conditioning system is used in an automobile, the predetermined space may be a boarding space on which a person is boarded.

The air conditioning system may include one outdoor unit and a plurality of indoor units connected thereto. Each indoor unit is installed in an independent space, and the air conditioning system can cool or heat each space. Conventionally, the air conditioning system thus configured has been controlled as described in the following prior art documents.

(1) Prior Art 1: Registered Patent No. 10-0468917, January 20, 2005 Registration

In the air conditioner, a plurality of indoor units are connected to one outdoor unit, and the opening degree of the electric expansion valve is controlled according to the discharge temperature of the compressor. Accordingly, the target discharge temperature that satisfies the suction superheat degree of the compressor in the optimum condition can be reached.

That is, in the conventional air conditioning system, the opening degree of each expansion valve is controlled to match the discharge temperature of the compressor. Specifically, the compressor is controlled by a weighted average sum of the set temperature difference of the space where each indoor unit is installed, and the opening degree of the expansion valve is adjusted to the capacity ratio of each indoor unit so as to match the discharge temperature of the compressor.

At this time, there is a limit in satisfying the set temperature of the space in which each indoor unit is installed. Accordingly, there has been a problem in that a cooling or heating medicine phenomenon occurs in a part of the space where each indoor unit is installed, so that the convenience of the user can not be satisfied.

Also, since the room temperature has not reached the set temperature for a relatively long time, the air conditioning system is operated inefficiently, which lowers the reliability of the user.

The present invention provides an air conditioning system having an outdoor unit and a plurality of indoor units connected thereto, the air conditioning system satisfying a discharge temperature of a compressor and a set temperature of a space in which each indoor unit is installed, and a control method thereof.

In particular, the present invention provides an air conditioning system and method for controlling the opening of each expansion valve so as to satisfy a discharge temperature and a set temperature of the compressor in accordance with a set temperature difference measured in each indoor unit.

The present invention also provides an air conditioning system and a control method thereof for determining the opening degree of at least a part of the expansion valves when the opening degree of the expansion valve is not adjusted and adjusting the opening amount again.

A control method of an air conditioning system according to an embodiment of the present invention is a control method of an air conditioning system having a plurality of indoor units arranged in different spaces and a plurality of expansion valves provided corresponding to the plurality of indoor units, The target opening amount for operating the compressor through the indoor unit having the largest difference between the set temperatures and for the temperature of the refrigerant discharged from the compressor to correspond to the predetermined appropriate discharge temperature is calculated and stored in the indoor temperature and the set temperature information of each indoor unit Calculating an opening ratio of each expansion valve by dividing the expansion amount of each expansion valve by the sum of opening amounts, calculating the opening ratio of each expansion valve, multiplying the target opening amount by the opening ratio, The amount of opening is determined and a plurality of expansion valves are controlled accordingly.

The air conditioning system is turned on, and the initial opening amount is determined by the capacity ratio of each corresponding indoor unit to each expansion valve, so that a plurality of expansion valves can be controlled.

The plurality of expansion valves are controlled to an initial opening amount, and information on the difference between the room temperature and the set temperature and the change rate thereof can be received through the indoor temperature sensor and the set temperature receiver provided in each indoor unit.

The operation frequency of the compressor and the opening amount of the expansion valve can be controlled through the received indoor information.

The operation frequency of the compressor and the opening amount of the expansion valve can be changed by receiving indoor information at a predetermined control cycle.

The operating frequency of the compressor can be controlled through the difference between the room temperature and the set temperature of the indoor unit having the largest difference between the room temperature and the set temperature and the rate of change.

The opening amount and opening ratio of the expansion valve may include only expansion valves corresponding to the indoor units to be operated among the plurality of indoor units.

The sum of the opening ratios may be one such that the sum of opening amounts of the plurality of expansion valves is the target opening amount.

It is possible to determine the target opening amount of each expansion valve, control the plurality of expansion valves accordingly, and measure the input and output pulse values of each expansion valve to determine whether the difference is zero.

An expansion valve having a difference between an input and an output pulse value of 0 is classified as an unrestricted expansion valve, and an expansion valve having a difference between input and output pulse values of 0 can be classified as a limited expansion valve.

When there is a limited expansion valve, the additional opening amount can be calculated by the difference between the sum of opening amounts of the plurality of expansion valves and the target opening amount.

The expansion ratio of the unshrouded expansion valve is divided by the sum of the opening amounts of the unconstrained expansion valves, and the expansion ratio of the expansion valve is calculated by multiplying the expansion ratio by the opening ratio and added to the individual target opening amounts of the respective expansion valves It is possible to determine the calculated corrected individual target opening amount, and thereby control a plurality of expansion valves.

The amount of opening of the plurality of expansion valves may be controllable within a predetermined range.

The air conditioning system according to the present invention includes a compressor, a plurality of indoor heat exchangers connected to the compressor, and a plurality of indoor heat exchangers arranged in a number corresponding to the plurality of indoor heat exchangers, And a control unit for controlling the compressor and the plurality of expansion valves, wherein the control unit includes: an indoor unit for receiving information on a difference between a room temperature and a set temperature of a space in which the plurality of indoor heat exchangers are installed, A compressor control unit for controlling an operation frequency of the compressor in accordance with a space having a largest difference between an indoor temperature and a set temperature, a target opening amount of the plurality of expansion valves in order to maintain an appropriate discharge temperature according to the operation of the compressor, A target opening amount calculation unit for calculating a difference, a difference between a room temperature and a set temperature of each space, An expansion ratio calculation unit for calculating an opening ratio according to an opening amount and a total opening amount of each expansion valve and a target opening amount of each expansion valve by multiplying the target opening amount by the opening ratio, And a target opening amount computing unit for controlling the target opening amount computing unit.

The control unit includes a pulse measurement unit for measuring the input and output pulses of each expansion valve, a restriction determination unit for determining whether there is a limited expansion valve whose input and output pulse values measured by the pulse measurement unit are not 0, And an additional opening amount calculation unit for calculating a difference between the target opening amount and the actual opening amount sum of the actual expansion valve to determine an additional opening amount when there is an expansion valve limited by the restriction determination unit, The metering calculation unit calculates the corrected target opening amount of each expansion valve by redistributing the additional opening amount to an unrestricted expansion valve whose input and output pulse values measured by the pulse measuring unit are 0, You can control the dosage.

According to the present invention, it is possible to satisfy both the proper discharge temperature of the compressor and the set temperature of each indoor unit in an air conditioning system having one outdoor unit and a plurality of indoor units.

Particularly, there is an advantage that a single set of compressors can set different set temperatures of different spaces provided with respective indoor units.

Also, since the compressor is controlled through the indoor unit having the largest set temperature difference among the indoor units, there is no cooling medication or heating medication, thereby providing comfort to the user.

Further, since each indoor unit is operated according to the set temperature difference and the rate of change thereof, it can be operated relatively efficiently and all the indoor units can satisfy the set temperature.

In addition, there is an advantage that the cycle can be normally operated and the set discharge temperature and the set temperature of each indoor unit can be satisfied by overcoming the problem due to mechanical limitations of the expansion valve and taking appropriate measures.

1 is a view illustrating an air conditioning system according to an embodiment of the present invention.
2 is a view illustrating the configuration of an air conditioning system according to an embodiment of the present invention.
3 is a view showing a control configuration of an air conditioning system according to an embodiment of the present invention.
4 is a flowchart illustrating a control operation of the air conditioning system according to an embodiment of the present invention.
5 is a diagram illustrating a control configuration of an air conditioning system according to another embodiment of the present invention.
6 is a flowchart illustrating a control flow of an air conditioning system according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

1 is a view illustrating an air conditioning system according to an embodiment of the present invention.

As shown in FIG. 1, the air conditioning system according to the present invention includes a plurality of indoor units 10 and at least one outdoor unit 20. In addition, a control unit 100 for controlling the indoor unit 10 and the outdoor unit 20 may be included.

In FIG. 1, connections between the indoor unit 10, the outdoor unit 20 and the control unit 100 are briefly shown. At this time, the control unit 100 may be provided as one configuration of the indoor unit 10 or the outdoor unit 20, but is illustrated as a separate configuration for convenience of explanation.

The indoor unit (10) and the outdoor unit (20) may be connected to each other by a refrigerant pipe so that the refrigerant flows and forms one refrigerant cycle. In addition, a distributor may be provided so that a plurality of indoor units 10 are connected to one outdoor unit 20 to be driven. Such a configuration is used in a general air conditioning system, and a detailed description thereof will be omitted.

The control unit 100 may be connected to the indoor unit 10 and the outdoor unit 20 through a communication line. That is, the control unit 100 may receive the driving information of the indoor unit 10 and the outdoor unit 20, and may issue a predetermined control command to the indoor unit 10 and the outdoor unit 20.

At this time, the control unit 100 may be variously connected to the indoor unit 10 and the outdoor unit 20. For example, the control unit 100 may be connected to the indoor unit 10 and the outdoor unit 20, respectively. The control unit 100 may be connected to the outdoor unit 20 and the outdoor unit 20 may be connected to the indoor unit 10.

Although one outdoor unit 20 is shown in FIG. 1, the outdoor unit 20 may be a plurality of outdoor units. 1, the indoor unit 10 is illustrated as a ceiling type indoor unit. However, the indoor unit 10 may be provided in various forms such as a stand type, a wall type, and the like. .

At this time, the plurality of indoor units 10 according to the present invention are arranged in different spaces. The different spaces include a space physically separated as well as a space in which the user thinks that the room temperature is different, and each indoor unit is controlled at a different set temperature. That is, it is understood that the plurality of indoor units 10 are arranged so as to have different indoor temperatures or set temperatures, respectively.

Hereinafter, each configuration of the indoor unit 10 and the outdoor unit 20 forming one refrigerant cycle will be briefly described.

2 is a view illustrating the configuration of an air conditioning system according to an embodiment of the present invention.

2, the air conditioning system according to the present invention includes a compressor 21, an outdoor heat exchanger 22, a plurality of indoor heat exchangers 11, 14, 17, and a plurality of expansion valves 31, 34, 37). At this time, the plurality of expansion valves 31, 34, 37 are arranged in a number corresponding to the number of the indoor heat exchangers 11, 14, 17 so as to be installed on one side of each of the indoor heat exchangers 11, 14, do.

Further, a four-way valve 23 is provided so that the air conditioning system can be driven in a cooling or heating mode.

When the air conditioning system is driven in the cooling mode, the refrigerant discharged from the compressor (21) flows from the four-way valve (23) to the outdoor heat exchanger (22). The refrigerant is condensed in the outdoor heat exchanger (22), branched and expanded by the plurality of expansion valves (31, 34, 37).

The refrigerant expanded in each of the expansion valves 31, 34 and 37 is evaporated in each of the indoor heat exchangers 11, 14 and 17 to cool the space in which the indoor heat exchangers 11, 14 and 17 are installed have. Also, the refrigerant discharged from the indoor heat exchangers (11, 14, 17) is mixed and flows into the compressor (21) again, and the above process can be repeated.

Meanwhile, when the air conditioning system is driven in the heating mode, the refrigerant discharged from the compressor 21 is branched from the four-way valve 23 to the indoor heat exchangers 11, 14 and 17. The space in which the indoor heat exchangers (11, 14, 17) are condensed and condensed in the indoor heat exchangers (11, 14, 17) can be heated.

The refrigerant discharged from each of the indoor heat exchangers (11, 14, 17) is expanded in each of the expansion valves (31, 34, 37) and evaporated in the outdoor heat exchanger (22). Then, the refrigerant passes through the four-way valve 23 and flows back to the compressor 21, and the above process can be repeated.

At this time, the discharge temperature of the compressor 21 and the thermal efficiency of the indoor heat exchangers 11, 14, and 17 can be changed by controlling the amount of opening of the expansion valves 31, 34 and 37.

Specifically, the flow rate of the refrigerant flowing in the cycle can be controlled according to the amount of opening of the expansion valves (31, 34, 37). In addition, the discharge temperature of the refrigerant passing through the compressor (21), that is, the discharge temperature of the compressor (21), varies depending on the flow rate of the refrigerant. Such a discharge temperature of the compressor 21 should be maintained at an appropriate temperature value (hereinafter referred to as an appropriate discharge temperature) to determine the capability of the compressor 21 and the capability of the entire system.

That is, the expansion valves 31, 34, and 37 can be controlled to satisfy an appropriate discharge temperature. At this time, the air conditioning system is provided with a discharge temperature sensor 24 for measuring the discharge temperature of the compressor (21). At this time, the amount of opening of the expansion valves 31, 34, 37 to satisfy the proper discharge temperature corresponds to the total amount of opening of all the expansion valves 31, 34, 37.

The ratio of the gas refrigerant to the liquid refrigerant in the indoor heat exchangers (11, 14, 17) can be controlled according to the amount of opening of the expansion valves (31, 34, 37). Accordingly, the heat exchange rates of the indoor heat exchangers 11, 14, and 17 are changed and the cooling efficiency or the heating efficiency of the space where the indoor heat exchangers 11, 14, and 17 are installed can be changed. At this time, the amount of opening of the expansion valves 31, 34, 37 for controlling the thermal efficiency of the indoor unit heat exchangers 11, 14, 17 corresponds to the amount of opening of each of the expansion valves 31, 34, 37.

In summary, the discharge temperature of the compressor 21 can be adjusted by the sum of the opening amounts of the plurality of expansion valves 31, 34, 37, and the opening degree of each expansion valve 31, 34, The thermal efficiency of the indoor heat exchangers 11, 14, and 17 can be adjusted.

Hereinafter, the control of the expansion valves 31, 34 and 37 will be described in detail.

3 is a view showing a control configuration of an air conditioning system according to an embodiment of the present invention.

As shown in FIG. 3, the control unit 100 includes various configurations. It is divided for convenience of explanation, and each configuration can be provided to perform various functions. Further, the names of the respective components are merely given for easy understanding.

In detail, the control unit 100 is provided with an indoor information receiving unit 110 for receiving the information of the indoor unit 10.

The plurality of indoor units 10 may be provided. In FIG. 3, the first indoor unit 10a, the second indoor unit 10b, and the third indoor unit c are exemplarily shown. Each of the indoor units 10 is provided with the above-described indoor heat exchangers 11, 14, and 17, respectively. At this time, it is assumed that one indoor heat exchanger (11, 14, 17) is installed in each indoor unit (10).

Accordingly, the first indoor heat exchanger 11, the second indoor heat exchanger 14, and the third indoor heat exchanger 17 may be provided. The first expansion valve 31, the second expansion valve 34 and the third expansion valve 37 are provided correspondingly.

Each of the indoor units 10 is provided with a room temperature sensor 12 and a set temperature receiving unit 13.

The room temperature sensor 12 is provided to measure the temperature of the space in which the indoor unit 10 is installed. For example, the indoor temperature sensor 12 is installed to measure the temperature of air before heat exchange with the indoor heat exchangers 11, 14, and 17 installed in the indoor unit 10.

In addition, the set temperature receiving unit 13 is provided to receive a room temperature (hereinafter referred to as a set temperature) required by the user. For example, the user inputs a set temperature using a communication device such as a remote controller, and the set temperature receiver 13 can store and transmit the temperature value.

As described above, each of the indoor units 10 may be provided with different room temperature and set temperature. For example, the room temperature of the space where the first indoor unit 10a is installed is 20 degrees, and the room temperature of the space where the second indoor unit 10b is installed may be 22 degrees. In addition, the first indoor unit 10a and the second indoor unit 10b may have the same room temperature.

The indoor information receiving unit 110 may receive information about the set temperature and the indoor temperature of each indoor unit 10. For example, the set temperature and the room temperature of the first indoor unit 10a are input to the indoor information receiving unit 110, and the temperature value may vary with time.

That is, the indoor information receiving unit 110 can receive information on the difference between the set temperature of each indoor unit and the room temperature (hereinafter referred to as the set temperature difference) and the rate of change thereof.

At this time, the indoor information receiving unit 110 may transmit the information on the indoor unit having the largest set temperature difference to the compressor controller 120. The set temperature difference may correspond to a temperature value at a certain point of time when the indoor information receiving unit 110 receives indoor information.

For example, when the set temperature difference of the first indoor unit 10a is 3, the set temperature difference of the second indoor unit 10b is 1, and the set temperature difference of the third indoor unit 10c is 2, 110 transmits information about the first indoor unit 10a to the compressor control unit 120. [ At this time, the information about the first indoor unit 10a corresponds to the set temperature difference and the rate of change thereof.

Accordingly, the compressor control unit 120 controls the compressor 21 through the information of the corresponding indoor unit. In detail, the frequency (Hz) can be controlled by the compressor (21) through the set temperature difference and the rate of change of the indoor unit.

The target opening amount calculation unit calculates an appropriate discharge temperature through the compressor 21 thus controlled. The appropriate discharge temperature corresponds to a temperature value at which the capacity of the compressor 21 and the ability of the system as a whole are optimized as described above. The calculation of such a suitable discharge temperature is generally used, and the detailed formula is omitted.

Further, the target opening amount calculation unit calculates a target opening amount for reaching the appropriate discharge temperature. At this time, the target opening amount corresponds to the total sum of opening amounts of the expansion valves through which refrigerant flows.

Meanwhile, the indoor information receiving unit 110 transmits information about each indoor unit 10 to the opening ratio calculator 140. The opening ratio calculator 140 calculates an opening amount of the expansion valve required for each indoor unit 10. For example, the opening amount of the first expansion valve 31 is calculated through the set temperature difference and the rate of change of the first indoor unit 10a, and the opening degree of the second indoor unit 10b The opening amount of the second expansion valve 34 is calculated.

Then, the opening ratio is calculated by dividing each opening amount by the sum of the opening amounts thus calculated. At this time, the opening ratio is a value possessed by each expansion valve, and can have different values.

In this manner, the opening amount of each expansion valve is calculated in the individual target opening amount calculation unit 150 using the values calculated in the target opening amount calculation unit 130 and the opening ratio calculation unit 140. [ Further, each expansion valve is controlled through the thus calculated value.

For the sake of understanding, the control of the air conditioning system will be described in detail with reference to Fig. 4, together with numerical examples. 3, the first to third indoor units 10a, 10b, 10c and the first to third expansion valves 31, 34, 37 are provided.

4 is a flowchart illustrating a control operation of the air conditioning system according to an embodiment of the present invention.

As shown in Fig. 4, the air conditioning system is turned on (S10). At this time, it is understood that the air conditioning system is turned ON when at least one of the plurality of indoor units is turned ON. The following control corresponds to the control for the indoor unit turned on and the corresponding expansion valve. Hereinafter, it is assumed that the first to third indoor units 10a, 10b, and 10c are turned ON.

After the air conditioning system is turned on, the initial opening amount is controlled (S20). At this time, the initial opening amount can be determined to be equal to the capacity ratio of the indoor unit. It is assumed that the first to third indoor units 10a, 10b, and 10c have the same capacity. That is, it is assumed that the initial opening amounts of the first to third expansion valves 31, 34, 37 are the same.

Then, the information of each indoor unit is received (S30). The indoor information corresponds to the set temperature difference and the rate of change of the space in which each indoor unit is installed, as described above. That is, the set temperature difference and the rate of change of the first to third indoor units 10a, 10b, 10c are transmitted to the indoor information receiving unit 110.

Based on the information received by the indoor information receiving unit 110, the indoor unit having the largest set temperature difference is extracted (S40). That is, one of the indoor units having the largest value is selected by comparing the set temperature difference of the first to third indoor units 10a, 10b, and 10c. If there are a plurality of indoor units having the largest value, one indoor unit can be selected in a predetermined order. For example, it is assumed that the first indoor unit 10a has the largest set temperature difference.

The compressor 21 is operated through the indoor information having the largest set temperature difference (S42). That is, the compressor control unit 120 determines and controls the operation frequency (Hz) of the compressor 21 through the set temperature difference and the rate of change of the first indoor unit 10a.

Then, a target opening amount for an appropriate discharge temperature according to the operation of the compressor 21 is calculated (S44). As described above, the target opening amount means the total opening amount of each expansion valve.

At this time, it is assumed that each expansion valve has opening amount of 0 to 10, and target opening amount is 10. Therefore, the appropriate discharge temperature can be reached when the sum of the opening amounts of the first to third expansion valves is operated to be 10, which is the target opening amount. At this time, the proper discharge temperature and target opening amount can be determined to be a predetermined range, but it is assumed that the target discharge amount is a certain value for the sake of understanding.

On the other hand, based on the information received by the indoor information receiving unit 110, the opening amount of each expansion valve is calculated (S50). That is, the opening amount of the first expansion valve 31 is calculated based on the set temperature difference of the first indoor unit 10a and the rate of change thereof. For example, it is assumed that the opening amount of the first expansion valve 31 is 2, the opening amount of the second expansion valve 34 is 2, and the opening amount of the third expansion valve 37 is 1.

Then, the opening ratio of each expansion valve is calculated (S55). The opening ratio corresponds to a value obtained by dividing the opening amount by the sum of opening amounts of the respective expansion valves. As in the above example, the sum of opening amounts of the respective expansion valves is equal to 5, and the opening ratio of the first expansion valve 31 is calculated as 2/5 to 0.4. The opening ratio of the second expansion valve 34 is 0.4 and the opening ratio of the third expansion valve 37 is 0.2.

The target opening amount thus calculated is multiplied by the opening ratio to determine the individual target opening amount (S60). The target opening amount of the first expansion valve 31 is determined to be 4 by multiplying the target opening amount 10 by the opening ratio 0.4 of the first expansion valve 31 as in the above example. Further, the target opening amount of the second expansion valve (34) is determined to be 4, and the target opening amount of the third expansion valve (37) is determined to be 2.

Each of the expansion valves is controlled by the determined target opening amount (S70). As a result, the total sum of the respective expansion valves corresponds to the target expansion amount and can be controlled to an appropriate discharge temperature. In addition, cooling or heating can be efficiently performed as the opening ratio of each expansion valve reflects information of each indoor unit.

Such control may be repeated through a predetermined control period until the air conditioning system is turned off (S80). The numerical values described above are arbitrarily determined values for convenience of explanation and are independent of actual values. Further, it can be controlled in the same manner through the opening amount change value of each expansion valve.

However, in this case, the opening value of the expansion valve may deviate from the limit. For example, when the target opening amount is 20 and the opening ratio of the first expansion valve 31 is 0.6, the target opening amount of the first expansion valve 31 is 12. The amount of opening of the first expansion valve 31 can not be controlled to 10, which is the limit of 10.

Accordingly, there arises a problem that the target opening amount is not satisfied and the proper discharge temperature can not be reached. Hereinafter, an air conditioning system having a method for overcoming such a problem and a control method thereof will be described.

5 is a diagram illustrating a control configuration of an air conditioning system according to another embodiment of the present invention. In FIG. 5, the description of the control configuration shown in FIG. 3 is cited, and only a part of the configuration is shown for convenience of explanation. Also, a plurality of expansion valves are provided and the first to third expansion valves 31, 34, 37 are provided.

As shown in FIG. 5, the control unit 100 is provided with a pulse measuring unit 160. The pulse measuring unit 160 is provided to measure the pulse values on both sides of the respective expansion valves 31, 34 and 37. That is, the values input to and output from the expansion valves 31, 34, and 37 can be measured.

Specifically, the expansion valves 31, 34, and 37 are controlled in opening amounts according to input pulse values. For convenience of explanation, it is assumed that the pulse value and opening amount are equal to each other. For example, when 2pulse is inputted, the amount of opening of the expansion valves 31, 34, 37 may be controlled to 2.

Also, the pulse value output from the expansion valves 31, 34, 37 may correspond to the opening amounts of the actual expansion valves 31, 34, 37. For example, if the opening amount is 2, 2 pulses can be output.

That is, the input and output pulse values of the expansion valves 31, 34, and 37 are the same. Accordingly, it can be determined that the expansion valves 31, 34, and 37 are normally operated when the pulse value difference becomes zero.

At this time, as described above, the target opening amount of the first expansion valve 31 is 12, and the opening amount of the first expansion valve 31 is controlled to be 10 by the limit of 10 in some cases. The input pulse value of the first expansion valve 31 may be 12 pulses corresponding to 12 or the output pulse value of the first expansion valve 31 may be 10 pulses corresponding to 10.

Therefore, it can be determined that the difference between the pulse values of the first expansion valve 31 is not zero and the first expansion valve 31 is abnormally operated.

The control unit 100 is provided with a restriction determination unit 170 for determining whether or not a difference between pulse values measured by the pulse measurement unit 160 is 0 or not. The restriction determination unit 170 divides the expansion valve having the difference of the measured pulse value of 0 into an unlimited expansion valve and sets the expansion valve whose difference in the measured pulse value is not 0 to a limited expansion valve Respectively.

In this case, the limitation is understood to mean that the inputted target opening amount is limited by the mechanical limit of the expansion valve. In other words, the restriction determination unit 170 determines whether or not there is a limited expansion valve among the expansion valves.

The control unit 100 further includes an additional opening amount calculation unit 180 for calculating the opening amount by comparing the opening amount calculated by the target opening amount calculation unit 130 with the current opening amount. The additional opening amount calculation unit 180 can calculate the additional opening amount only when it is determined that the restricted expansion valve exists by the restriction determination unit 170. [

The additional opening amount thus calculated may be transmitted to the individual target opening amount calculating unit 150 and distributed again. At this time, the distribution is limited to the opening ratio, but the limited expansion valve is excluded. That is, it can be redistributed according to the opening ratio between the unconstrained expansion valves. Further, each expansion valve is controlled through the thus calculated value.

For the sake of understanding, the control of the air conditioning system will be described in detail with reference to FIG. 6, together with numerical examples. 3 and 5, the first to third indoor units 10a, 10b and 10c and the first to third expansion valves 31, 34 and 37 are provided.

6 is a flowchart illustrating a control flow of an air conditioning system according to another embodiment of the present invention. Further, Fig. 6 can be understood as a control following Fig. Accordingly, each expansion valve is controlled by the target opening amount as shown in Fig. 4 (S80).

Numerally, for example, it is assumed that the target opening amount is 20 and the opening ratio of the first to third expansion valves 31, 34, 37 is 0.6: 0.2: 0.2. Accordingly, individual target opening amounts correspond to 12, 4, and 4, respectively. Such numerical values are determined arbitrarily for convenience of explanation and are not related to actual values.

Then, the pulse value of each expansion valve is measured (S90). At this time, the pulse value means the pulse value input to each expansion valve and the output pulse value. In detail, the difference between the input and output pulse values can be measured for each expansion valve.

Accordingly, it is determined whether or not there is a limited expansion valve (S100). As described above, when the difference in pulse value is not 0, it is classified as a limited expansion valve, and when there is any such expansion valve, it is determined that there is a limited expansion valve.

If there is no limited expansion valve, control is terminated. It is not necessary to adjust the opening degree of the expansion valve when all of the expansion valves normally operate and the target opening amount is satisfied.

On the other hand, when there is a limited expansion valve, an additional opening amount is calculated (S110). The additional opening amount can be obtained by subtracting the actual opening amount from the target opening amount, or can be calculated as a value that the limited expansion valve does not satisfy.

The target opening amount of the first expansion valve 31 is 12, but the limit of the first expansion valve 31 is 10, and the actual opening amount is 10 as in the above example. Accordingly, the difference in pulse value is measured as non-zero, and it is determined that there is a limited expansion valve. Therefore, when the additional expansion amount is calculated, the first expansion valve 31 is not satisfied by 2, and the additional opening amount becomes 2.

Further, the opening ratio of the expansion valve, which is determined to be unrestricted, is calculated (S120). At this time, the opening ratio is calculated by subtracting the limited expansion valve from the opening ratio determined above. As in the previous example, the opening ratio is 0.6: 0.2: 0.2, but the first expansion valve 31 is excluded as a limited expansion valve. Accordingly, the open ratio of the second and third expansion valves 34 and 37, which is not limited, becomes 0.5: 0.5.

Further, the target opening amount is corrected in addition to the opening degree of each expansion valve by multiplying the opening ratio of the expansion valve not limited to the additional opening amount. Then, each of the expansion valves is controlled by the modified target opening amount (S130).

1 is added to the second and third expansion valves 34 and 37 by multiplying the additional expansion amount 2 by the opening ratio 0.5 of the second and third expansion valves 34 and 37, respectively, as in the foregoing example. thereafter. The opening degree of each of the second and third expansion valves 34 and 37 becomes 5 + 4 + 1. As a result, the opening degrees of the first to third expansion valves 31, 34 and 37 correspond to 10, 5, and 5, and satisfy the target opening amount.

In this manner, it is possible to overcome the problem due to the structural limitation of the expansion valve, satisfy the target opening amount, and maximize the efficiency of each indoor unit at the same time.

10: indoor unit 31, 34, 37: expansion valve
100: control unit 130: target opening amount calculating section
140: opening ratio calculation unit 150: individual target opening amount calculation unit
160: pulse measuring unit 170:
180: additional opening amount calculating section

Claims (15)

A control method for an air conditioning system having a plurality of indoor units arranged in different spaces and a plurality of expansion valves provided corresponding to the plurality of indoor units,
The compressor is operated through the indoor unit having the largest difference between the indoor temperature and the set temperature,
Calculating a target opening amount for allowing the temperature of the refrigerant discharged from the compressor to correspond to a predetermined appropriate discharging temperature,
Calculates an opening amount of each expansion valve according to room temperature and set temperature information of each indoor unit,
Dividing the opening amount of each expansion valve by the sum of opening amounts, calculating the opening ratio of each expansion valve,
Multiplying the target opening amount by the opening ratio to determine an individual target opening amount of each expansion valve, thereby controlling a plurality of expansion valves,
And determining whether the difference is 0 by measuring input and output pulse values of each expansion valve. The method according to claim 1,
When the air conditioning system is turned ON,
Wherein the initial opening amount is determined by the capacity ratio of each of the indoor units corresponding to each expansion valve, and a plurality of expansion valves are controlled accordingly. 3. The method of claim 2,
The plurality of expansion valves are controlled to an initial opening amount,
And receiving information on a difference between a room temperature and a set temperature and a rate of change thereof through an indoor temperature sensor and a set temperature receiver provided in each indoor unit. The method of claim 3,
Wherein the control unit controls the operation frequency of the compressor and the opening amount of the expansion valve through the received indoor information. 5. The method of claim 4,
Wherein the controller receives the indoor information at a predetermined control cycle and changes the operation frequency of the compressor and the opening amount of the expansion valve. The method according to claim 1,
Wherein the operation frequency of the compressor is controlled through the difference between the indoor temperature and the set temperature of the indoor unit having the largest difference between the indoor temperature and the set temperature, and the rate of change thereof. The method according to claim 1,
Wherein the calculation of opening amount and opening ratio of the expansion valve includes only the expansion valve corresponding to the indoor unit operated in the plurality of indoor units. The method according to claim 1,
Wherein the sum of the opening ratios is one such that the sum of opening amounts of the plurality of expansion valves is the target opening amount. delete The method according to claim 1,
An expansion valve having a difference between the input and output pulse values of 0 is classified as an unrestricted expansion valve,
A control method for an air conditioning system in which an expansion valve whose difference between input and output pulse values is not zero is classified as a limited expansion valve. 11. The method of claim 10,
Wherein the additional opening amount is calculated based on a difference between the sum of opening amounts of the plurality of expansion valves and the target opening amount when a limited expansion valve exists. 12. The method of claim 11,
The opening ratio of the uncompressed expansion valve is divided by the sum of the opening amount of the uncompressed expansion valve to calculate the opening ratio of the uncompressed expansion valve,
Wherein the plurality of expansion valves are controlled by multiplying the additional opening amount by the opening ratio to determine the corrected individual target opening amount calculated in addition to the individual target opening amounts of the respective expansion valves. The method according to claim 1,
Wherein the opening amounts of the plurality of expansion valves are controllable within a predetermined range. compressor;
A plurality of indoor heat exchangers connected to the compressor;
A plurality of expansion valves provided corresponding to the plurality of indoor heat exchangers and disposed on one side of each indoor heat exchanger; And
And a control unit for controlling the compressor and the plurality of expansion valves,
In the control unit,
An indoor information receiving unit for receiving information about a difference between a room temperature and a set temperature of a space in which the plurality of indoor heat exchangers are installed and a rate of change thereof;
A compressor control unit for controlling an operation frequency of the compressor according to a space having a largest difference between a room temperature and a set temperature;
A target opening amount calculation unit for calculating a target opening amount of the plurality of expansion valves to maintain an appropriate discharge temperature according to the operation of the compressor;
An opening ratio calculator for calculating an opening ratio according to the opening amount and the total opening amount of each expansion valve according to the difference between the room temperature and the set temperature of each space and information on the rate of change;
An individual target opening amount calculation unit for calculating a target opening amount of each expansion valve by multiplying the target opening amount by the opening ratio and controlling the opening amount of each expansion valve;
A pulse measurement unit for measuring input and output pulse values of each expansion valve;
A restriction determination unit for determining whether there is a limited expansion valve in which the input and output pulse values measured by the pulse measurement unit are not 0; And
And an additional opening amount calculation unit for calculating the difference between the target opening amount and the actual opening amount sum of the actual expansion valve when there is an expansion valve limited by the restriction determination unit, system. 15. The method of claim 14,
The individual target opening amount calculating section calculates the corrected target opening amount of each expansion valve by redistributing the additional opening amount to an unrestricted expansion valve whose input and output pulse values measured by the pulse measuring section are 0, And the amount of opening of the expansion valve is controlled.

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