KR20090022556A - Multi-type air conditioner and control method thereof - Google Patents

Abstract

A multi-type air conditioner and a control method thereof are provided to minimize the cooling performance degradation of a wall-mounted type indoor unit generated when a stand type indoor unit and a wall-mounted indoor unit operate at the same time by increasing the extent of opening in an electronic expansion valve of the wall-mounted type indoor. When a first indoor unit(50) of a multi-type air conditioner and a second indoor unit(70) having smaller air conditioning volume than the volume of the first indoor unit operates at the same time, whether cooling is normally performed or not is determined in a first indoor space in which the first indoor unit is installed and a second indoor space in which the second indoor unit is installed. The extent of opening in an electronic expansion valve of the second indoor unit is increased when cooling is not normally performed in the first indoor space and the second indoor space.

Description

Multi-type air conditioner and control method

The present invention relates to a multi-type air conditioner and a control method thereof, and more particularly, to reduce the cooling performance of the wall-mounted indoor unit by controlling the opening degree of the wall-mounted indoor unit-side electromagnetic expansion valve during simultaneous operation of the stand type indoor unit and the wall-mounted indoor unit. It relates to a multi-type air conditioner that can be minimized and a control method thereof.

In general, an air conditioner is a device used for cooling or heating a room. The air conditioner circulates a refrigerant between an indoor unit and an outdoor unit to absorb ambient heat when the liquid refrigerant evaporates and heats it when liquefied. The cooling or heating action is performed by the characteristic of emitting the air, and the cooling or heating action of the air conditioner is determined according to the circulation direction of the refrigerant.

In general, air conditioners install one indoor unit in one outdoor unit, but recently, a plurality of indoor units having various shapes and capacities are connected to at least one outdoor unit, so that a large number of separated spaces such as a school, a company, and a building are used. Increasingly, users' demands for multi-type air conditioners that perform cooling or heating operations for dogs are increased.

As described above, in a two-room (or three-room) multi-type air conditioner in which one indoor unit and a wall-mounted indoor unit are connected to each outdoor unit, when the stand-type indoor unit and the wall-mounted indoor unit are operated simultaneously, the calculation capacity of each indoor unit is summed. The outdoor unit will be controlled.

However, if both indoor spaces where indoor units are installed are not normally cooled during the simultaneous operation of the stand type indoor unit and the wall-mounted indoor unit, the concentration of refrigerant occurs on the stand type indoor unit with a large cooling capacity, resulting in cooling performance of the stand type indoor unit. Is gradually improved over time, whereas the cooling performance of the wall-mounted indoor unit gradually decreases with time (see FIG. 5 (a)). There was a problem that it is difficult to feel the comfort (cool) by driving.

Accordingly, the present invention is to solve the above problems, the object of the present invention is The present invention provides a multi-type air conditioner capable of minimizing the deterioration in cooling performance of a wall-mounted indoor unit that may occur during simultaneous operation of a stand indoor unit and a wall-mounted indoor unit.

A control method of a multi-type air conditioner according to the present invention for achieving the above object is a first indoor unit in which the first indoor unit is installed during simultaneous operation of a first indoor unit and a second indoor unit having a smaller cooling capacity than the first indoor unit. Determining whether cooling of the space and the second indoor space in which the second indoor unit is installed is normally performed; When it is determined that cooling of the first indoor space and the second indoor space is not normally performed, the opening degree of the second indoor unit side electromagnetic expansion valve is increased.

In addition, it is determined whether the cooling is normally performed when the simultaneous operation time is more than the set time.

In addition, if the room temperature change amount of the first indoor space and the second indoor space is more than 0 (zero), it is determined that the cooling is not performed normally.

The indoor temperature change amount is a value obtained by subtracting an indoor temperature at the start of the simultaneous operation from an indoor temperature after the preset time operation.

In addition, when it is determined that the cooling is not performed normally, the opening degree of the first and second indoor unit side electromagnetic expansion valves is checked.

Further, when the value obtained by subtracting the opening degree of the second indoor unit side electromagnetic expansion valve from the opening degree of the first indoor unit side electromagnetic expansion valve is greater than or equal to a set value, the opening degree of the second indoor unit side electromagnetic expansion valve is increased to a setting step.

Multi-type air conditioner according to the present invention for achieving the above object is a first indoor unit; A second indoor unit having a cooling capacity smaller than that of the first indoor unit; First and second indoor unit side electromagnetic expansion valves configured to adjust a flow rate of the refrigerant; In the simultaneous operation of the first and the second indoor unit, it is determined whether cooling of the first indoor space in which the first indoor unit is installed and the second indoor space in which the second indoor unit is normally performed, and the first indoor space and the first indoor space are performed. 2, if it is determined that the cooling of the indoor space is not normal, and includes an outdoor control unit for increasing the opening degree of the electromagnetic expansion valve of the second indoor unit.

In addition, the outdoor controller determines that the cooling is not normally performed when the indoor temperature change amount of the first indoor space and the second indoor space is zero or more.

In addition, when it is determined that the cooling is not normally performed, the outdoor controller checks the opening degree of the first and second indoor unit side electromagnetic expansion valves.

The outdoor control unit may set the opening degree of the second indoor unit-side electromagnetic expansion valve when the value obtained by subtracting the opening degree of the second indoor unit-side electromagnetic expansion valve from the opening degree of the first indoor unit-side electromagnetic expansion valve is a set value or more. To increase.

According to the present invention, by increasing the opening degree of the wall-mounted indoor unit-side electronic expansion valve, there is an effect of minimizing the cooling performance deterioration of the wall-mounted indoor unit that may occur during simultaneous operation of the stand-type indoor unit and the wall-mounted indoor unit.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a refrigerant flow path of a multi-type air conditioner according to an embodiment of the present invention, in this embodiment, a state in which two indoor units 50 and 70 having different cooling capacities are connected to one outdoor unit 10 as an example. Explain, but focus on the cooling cycle.

As shown in FIG. 1, the multi-type air conditioner according to the present embodiment includes one outdoor unit 10 forming a normal cooling cycle, a first indoor unit 50 (stand type indoor unit) connected to the outdoor unit 10, and a second outdoor unit 10. A indoor unit 70 (for example, a wall-mounted indoor unit) (for example, the cooling capacity of the first indoor unit 50 is 18 equilibrium, and the cooling capacity of the second indoor unit 70 is 6 equilibrium), and the first and second units. A refrigerant pipe is installed between the indoor units 50 and 70 and the outdoor unit 10.

The outdoor unit 10 includes a plurality of compressors A and B 12a and 12b for compressing a refrigerant into a gaseous state of high temperature and high pressure, and high temperature and high pressure compressed by compressors A and B 12a and 12b. The outdoor heat exchanger 14 receives heat from the gas refrigerant and exchanges heat with the outdoor air, and the outdoor fan 16 regulates the outdoor air flow by the outdoor fan motor 18 to increase the heat exchange capacity of the outdoor heat exchanger 14. It includes.

The high pressure side pipe connected to the first and second indoor units 50 and 70 in the pipe of the outdoor heat exchanger 14 controls the flow rate of the refrigerant flowing to the first and second indoor units 50 and 70 through superheat control. First and second electromagnetic expansion valves 20 and 22 are provided.

In addition, the suction side of the compressors A and B 12a and 12b includes an accumulator 24 for introducing only the gaseous refrigerant into the compressors A and B 12a and 12b, and the compressors A and B 12a and 12b. On the discharge side of the check valve 26a, in order to prevent the starting failure of the compressor to be driven later by the discharge pressure of the compressor which is driven first when only one of the two compressors 12a and 12b is driven. 26b) is installed.

A hot gas bypass pipe 28a is provided between the discharge high pressure pipes of the compressors A and B 12a and 12b and the suction low pressure pipe to bypass a part of the hot gas from the compressors A and B 12a and 12b. In the middle of the hot gas bypass pipe 28a, a bypass valve 28 for adjusting the amount of refrigerant of the hot gas being bypassed is provided.

Compressors A and B (12a, 12b) have two different capacities (40%, 60%) and a tandem in which the capacity changes up to three stages (40%, 60%, 100%) as a single or simultaneous operation. Compressor can be used and can be configured in various ways as needed.

The first and second indoor unit (50, 70) of the first and second indoor heat exchangers (52, 72) and the first and second indoor heat exchangers (52, 72) for receiving a refrigerant and heat exchange with the indoor air First and second indoor fans 54, 64 for regulating indoor air flow by the first and second indoor fan motors 56, 76 to increase heat exchange capacity.

Meanwhile, the first high pressure side pipe connection service valve 40 and the first low pressure side pipe connection service valve 42 are installed in the refrigerant pipes of the outdoor unit 10 and the first indoor unit 50, and the outdoor unit 10 is installed. The second high pressure side pipe connection service valve 44 and the second low pressure side pipe connection service valve 46 are installed in the refrigerant pipe of the second indoor unit 70.

Figure 2 is a control block diagram of a multi-type air conditioner according to an embodiment of the present invention, Figure 3 is a block diagram showing in detail the indoor unit shown in Figure 2, the multi-type air conditioner according to this embodiment is an outdoor control unit It consists of the outdoor unit 10 including 11, and the two indoor units 50 and 70 containing the indoor control parts 51 and 71, respectively.

The outdoor unit 10 includes an outdoor control unit 11, a compressor driving unit 13, compressors 12a and 12b, an outdoor fan driving unit 18, an outdoor fan 16, an electromagnetic expansion valve driving unit 15, first and second It comprises a solenoid expansion valve (20, 22).

The outdoor control unit 11 is a microcomputer that controls the overall operation of the outdoor unit 10, and the first indoor unit and the second indoor unit in which the first indoor unit 50 is installed during simultaneous operation of the first and second indoor units 50 and 70. It is determined whether the cooling of the second indoor space in which the 70 is installed is normally performed, and if it is determined that the cooling of the first indoor space and the second indoor space is not normally performed, the electronic expansion valve 22 of the second indoor unit 70 side. By increasing the degree of opening) it is possible to minimize the decrease in the cooling performance of the second indoor unit (70).

The compressor driver 13 controls the compressors A and B 12a and 12b to operate alone or simultaneously according to the compressor control signal of the outdoor controller 11, and the outdoor fan driver 18 controls the outdoor of the outdoor controller 11. The driving of the outdoor fan 16 is controlled according to the fan control signal.

The electromagnetic expansion valve driver 15 controls the opening degrees of the first and second electromagnetic expansion valves 20 and 22 according to the electromagnetic expansion valve control signal of the outdoor controller 11.

In addition, each indoor unit (50, 70), as shown in Figure 3, the power supply unit 53, the input unit 55, the room temperature sensor 57, the indoor control unit 51, the indoor fan drive unit 56, the indoor fan ( 54), the louver driver 58, the upper and lower louvers 59a, the left and right louvers 59b, and the display unit 60 (in Fig. 3, the reference numerals are denoted based on the first indoor unit 50). Indicated).

The power supply unit 53 converts the commercial AC voltage supplied from the AC power supply terminal (not shown) into a predetermined DC voltage necessary for the operation of the indoor units 50 and 70 and outputs the same.

Input unit 55 allows the user to input the desired operation mode (automatic, cooling, dehumidification, blowing, heating, etc.) of the air conditioner, the start / stop of operation, the desired temperature, the set air volume and the set wind direction of the discharged air A plurality of keys are included in the first and second indoor units 50 and 70 or the remote controller, and the indoor temperature detecting unit 57 detects the temperature of the indoor air sucked into the first and second indoor units.

The indoor controllers 51 and 71 not only initialize the indoor units 50 and 70 by receiving the DC voltage output from the power supply unit 53, but also according to the operation mode and the operation start / stop signal selected through the input unit 55. As a microcomputer that controls the overall operation of the indoor units 50 and 70, the indoor temperature of the first and second indoor spaces detected by the indoor temperature detecting unit 57 is received and transmitted to the outdoor control unit 11.

The indoor fan driver 56 receives a control signal output from the indoor controllers 51 and 71 to blow the heat exchanged air (cold and warm air) into the room according to the selected air volume through the input unit 55. , 74), and the louver driver 58 adjusts the angles of the up, down, left, and right louvers 59a, 59b according to the control signals of the indoor controllers 51, 71 to adjust the direction of the discharged air up, down, left, and right. .

The display unit 60 displays an operation mode (automatic, cooling, dehumidifying, blowing, heating, etc.) input by the user through the input unit 55, a desired temperature, and an indoor temperature.

Hereinafter, a control method of a multi-type air conditioner according to an embodiment of the present invention will be described with reference to FIG. 4.

First, indoor control units 51 and 71 of each indoor unit 50 or 70 start operation of each indoor unit 50 or 70 when a user inputs an operation start signal through the input unit 55 (105). At this time, each indoor control unit 51, 71 transmits a signal (operation signal) that is in operation to the outdoor control unit 11 when the operation of its indoor units 50, 70 starts.

Thereafter, the outdoor control unit 11 that receives the operation signals of the indoor units 50 and 70 from each of the indoor control units 51 and 71 determines whether the first indoor unit 50 and the second indoor unit 70 are operating at the same time ( 110).

If it is determined that the operation is simultaneous (YES in step 110), the outdoor controller 11 checks the indoor temperature Ta of the first indoor space and the indoor temperature Tb of the second indoor space at the start of the simultaneous operation. (115). The indoor temperatures Ta and Tb are detected by the indoor temperature detecting unit 57 and transmitted to the outdoor control unit 11 in real time via the indoor control units 51 and 71.

Next, the outdoor controller 11 determines whether the simultaneous operation time of the first indoor unit 50 and the second indoor unit 70 has reached the first set time (120). If it has not been reached (NO in step 120), simultaneous operation is continued until the first set time is reached, and if the simultaneous operation time has reached the first set time (YES in step 120). The room temperature Ta 'of the first indoor space and the room temperature Tb' of the second indoor space after the first set time operation are checked (125).

Thereafter, the outdoor controller 11 determines whether the indoor temperature change amount Ta'-Ta of the first indoor space and the indoor temperature change amount Tb'-Tb of the second indoor space are equal to or greater than zero (130). If the room temperature change amount of the first and second indoor spaces is equal to or greater than 0 (YES in step 130), the opening degree step Sa of the first indoor unit side electromagnetic expansion valve and the opening degree step Sb of the second indoor unit side electromagnetic expansion valve Check (135). Herein, the change in the indoor temperature of the first and second indoor spaces is equal to or greater than 0, indicating that there is no change in the indoor temperature or the room temperature rises even though the cooling operation is performed during the first set time. It means that the indoor space is not normally cooled. This phenomenon may occur when there are too many people in the indoor space, or when the indoor space to be cooled is too large (for example, 18 pyeong) compared to the cooling capacity of the indoor unit (for example, 6 pyeong).

Next, the outdoor control unit 11 subtracts the opening degree step Sb of the second indoor unit side electromagnetic expansion valve from the opening degree step Sa of the first indoor unit side electromagnetic expansion valve identified in step 135, and the set value Sa-Sb is the set value. If it is determined that it is abnormal (140), if it is equal to or greater than the set value (YES in step 140), the opening degree of the second indoor unit-side electromagnetic expansion valve is increased to a predetermined step and then the first time is set for the second setting time. The indoor unit 50 and the second indoor unit 70 are driven (145). Here, the predetermined step is a value determined by experiment according to the cooling capacity and the model of the first indoor unit 50 and the second indoor unit 70 coupled to the outdoor unit 10.

On the other hand, when the first indoor unit 50 or the second indoor unit 70 operates alone (NO in step 110), the room temperature change amount of at least one of the first and second indoor spaces is less than zero. (No at step 130), ③ When the opening degree step of the first indoor unit side electromagnetic expansion valve is subtracted from the opening step of the second indoor unit side electromagnetic expansion valve (Sa-Sb) is less than the set value (at step 140). 'No'), ④ When the first indoor unit 50 and the second indoor unit 70 are operated for a second set time after increasing the opening degree of the second indoor unit side electromagnetic expansion valve to a predetermined step, In this case, the opening of each of the electromagnetic expansion valves 20 and 22 is controlled in a conventional manner and the air conditioner is operated 150.

Thereafter, the outdoor controller 11 determines whether the single operation or simultaneous operation time of the first and second indoor units 50 and 70 has reached the third set time (155). If the set time has not been reached (NO in step 155), single operation or simultaneous operation is continued until the third set time is reached, and the single operation or simultaneous operation time reaches the third set time. If yes (YES in step 155), the process returns to step 110 to determine whether the first indoor unit 50 and the second indoor unit 70 are simultaneously operated.

5 is a graph showing the cooling performance according to the passage of time during the simultaneous operation of the first indoor unit 50 (stand-type indoor unit) and the second indoor unit (70, wall-mounted indoor unit), wherein the thick solid line represents the case of the first indoor unit , The thick dotted line indicates the case of the second indoor unit.

When the first indoor unit 50 and the second indoor unit 70 is operated at the same time when the cooling of the first indoor space in which the first indoor unit 50 is installed and the second indoor space in which the second indoor unit 70 is installed is not normally performed. (When the change in the indoor temperature of the first and second indoor space is greater than or equal to zero), the concentration phenomenon of the refrigerant occurs toward the first indoor unit 50 having a large cooling capacity, and as shown in FIG. While the cooling performance on the 50 side continuously improves with the passage of time, the cooling performance on the second indoor unit 70 side continuously decreases with the passage of time. There is a problem that it is difficult to feel the comfort (cool). However, according to the control method according to an embodiment of the present invention, as shown in FIG. 5B, the cooling performance of the first indoor unit 50 and the cooling performance of the second indoor unit 70 are relatively uniform. The user existing in the first indoor space as well as the users existing in the second indoor space can feel the comfort (cool) according to the cooling operation (not greatly improved or degraded with the passage of time). That is, the first indoor space and the second indoor space can simultaneously enjoy a cooling effect of a relatively uniform degree.

1 is a refrigerant flow diagram of a multi-type air conditioner according to an embodiment of the present invention.

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

FIG. 3 is a detailed block diagram illustrating the indoor unit shown in FIG. 2.

4 is a flowchart illustrating a control method of a multi-type air conditioner according to an embodiment of the present invention.

5 is a graph showing the cooling performance according to the passage of time during the simultaneous operation of the stand-type indoor unit and the wall-mounted indoor unit, (a) is a graph when there is a technical problem (before the problem is solved), (b) is It is a graph when the control method according to an embodiment of the present invention is applied (where a thick solid line represents a case of a stand type indoor unit, and a thick dashed line represents a case of a wall-mounted indoor unit).

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

10: outdoor unit 11: outdoor control unit

15: electromagnetic expansion valve drive unit 20, 22: first and second electromagnetic expansion valve

50, 70: 1st and 2nd indoor unit 51, 71: 1st and 2nd indoor control part

57: room temperature detection unit

Claims (10)

Whether or not cooling of the first indoor unit and the second indoor unit in which the second indoor unit is normally performed is simultaneously performed when the first indoor unit and the second indoor unit having a cooling capacity smaller than the first indoor unit are simultaneously operated. Judge; If it is determined that cooling of the first indoor space and the second indoor space is not performed normally, the control method of the multi-type air conditioner increases the opening degree of the electromagnetic expansion valve of the second indoor unit; The method of claim 1, Control method of the multi-type air conditioner to determine whether the cooling is normally performed when the simultaneous operation time is more than the set time The method of claim 2, Control method of the multi-type air conditioner to determine that the cooling is not normally performed if the change in the room temperature of the first indoor space and the second indoor space is more than zero (zero) The method of claim 3, wherein The indoor temperature change amount is a control method of a multi-type air conditioner, which is a value obtained by subtracting an indoor temperature at the start of the simultaneous operation from an indoor temperature after the set time operation. The method of claim 1, If it is determined that the cooling is not normal, the control method of the multi-type air conditioner to check the opening degree of the first and second indoor unit side expansion valve The method of claim 5, wherein If the value obtained by subtracting the opening degree of the second indoor unit side electromagnetic expansion valve from the opening degree of the first indoor unit side electromagnetic expansion valve is greater than or equal to a set value, the multi-type air for increasing the opening degree of the second indoor unit side electromagnetic expansion valve to a setting step Harmonic Control Method A first indoor unit; A second indoor unit having a cooling capacity smaller than that of the first indoor unit; First and second indoor unit side electromagnetic expansion valves configured to adjust a flow rate of the refrigerant; In the simultaneous operation of the first and the second indoor unit, it is determined whether cooling of the first indoor space in which the first indoor unit is installed and the second indoor space in which the second indoor unit is normally performed, and the first indoor space and the first indoor space are performed. 2 If it is determined that the cooling of the indoor space is not normal, the multi-type air conditioner including an outdoor control unit for increasing the opening degree of the electromagnetic expansion valve on the second indoor unit side The method of claim 7, wherein The outdoor controller is a multi-type air conditioner for determining that the cooling is not normally performed if the indoor temperature change amount of the first indoor space and the second indoor space is more than zero (zero) The method of claim 7, wherein The outdoor control unit is a multi-type air conditioner for checking the opening degree of the first and second indoor unit side expansion valve when it is determined that the cooling is not normal The method of claim 9, The outdoor control unit sets the opening degree of the second indoor unit-side electromagnetic expansion valve to a setting step when a value obtained by subtracting the opening degree of the second indoor unit-side electromagnetic expansion valve from the opening degree of the first indoor unit-side electromagnetic expansion valve is equal to or greater than a set value. Increasing Multi Air Conditioner

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