KR100733313B1 - Process for controling pressure and calculating target pressure of indoor heat exchanger in air conditioner - Google Patents

Abstract

In the indoor heat exchanger pressure control method of a multi-type air conditioner according to the present invention, a multi-type air conditioner is set by setting a target pressure of an indoor heat exchanger according to a temperature change of an indoor / outdoor, and adjusting a pressure of an indoor heat exchanger according to the target pressure. There is an effect of improving the efficiency.

Description

Process for controlling pressure and calculating target pressure of indoor heat exchanger in air conditioner

1 is a schematic perspective view showing a multi-type air conditioner according to a first embodiment of the present invention

2 is a block diagram showing an outdoor unit of the multi-type air conditioner according to the first embodiment of the present invention.

3 is a flowchart illustrating a method of controlling an indoor heat exchanger pressure during cooling of a multi-type air conditioner according to a first embodiment of the present invention.

4 is a flowchart illustrating a method of controlling an indoor heat exchanger pressure during heating of a multi-type air conditioner according to a second embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

11, 12, 13, 14: indoor unit 21, 22: outdoor unit

51: indoor heat exchanger 54: indoor expansion valve

61: accumulator 62: inverter compressor

63: constant speed compressor 64: oil separator

65: four-way valve 66: capillary tube

70: outdoor heat exchanger 74: outdoor electromagnetic expansion valve

80: subcooler 82: subcooler

84: bypass piping 85: check valve

86: electromagnetic expansion valve 87: recovery piping

90: liquid injection device

101, 102, 103, 104, 105, 106: temperature sensor

The present invention relates to an indoor heat exchanger pressure control method and a target pressure calculation method of an air conditioner, the indoor heat exchanger pressure control method and the target pressure of the air conditioner to set the target pressure of the indoor heat exchanger according to the indoor / outdoor temperature It is about a calculation method.

Conventional multi-type air conditioner is composed of one or more outdoor units and a plurality of indoor units, the indoor unit and the outdoor unit is connected via a refrigerant pipe.

The outdoor unit of the multi-type air conditioner according to the prior art includes an accumulator extracting only gas refrigerant from the refrigerant supplied from the indoor unit, a compressor receiving and compressing the gas refrigerant extracted from the accumulator, and a refrigerant compressed in connection with the compressor. It comprises a four-way valve for selecting a flow path, and an outdoor heat exchanger for heat exchange between the refrigerant supplied from the four-way valve and the outdoor air.

The refrigerant heat exchanged in the outdoor heat exchanger is supplied to the indoor heat exchanger of the indoor unit through the refrigerant pipe.

Here, the multi-type air conditioner according to the prior art is driven by a cooling / heating cycle to cool / heat the room.

In particular, in order to increase the efficiency of the air conditioner, the refrigerant pressure of the indoor heat exchanger is set to a predetermined pressure during cooling / heating, and the controller of the multi-type air conditioner is configured to maintain the pressure of the indoor heat exchanger at a predetermined pressure. To control.

However, since the multi-type air conditioner according to the prior art maintains the same pressure at all temperature conditions at all times without considering indoor / outdoor temperature differences, it is not only excessively operated under overload conditions but also does not adequately cope with indoor and outdoor loads.

The present invention has been made to solve the above problems, and provides a pressure control method and a target pressure calculation method of the indoor heat exchanger of the air conditioner to adjust the target pressure of the indoor heat exchanger in consideration of the indoor / outdoor temperature. There is a purpose.

The indoor heat exchanger pressure control method of the air conditioner according to the first aspect of the present invention for solving the above technical problem is a step of receiving a pre-stored reference low pressure (Ps) (S10); Sensing the indoor / outdoor temperature through the temperature sensors 55 and 25 installed in the indoor unit and the outdoor unit and receiving the detected indoor / outdoor temperature Tin '/ Tout' (S20); Factor (F) is determined by the difference between the sum of indoor / outdoor temperatures (Tin / Tout), the temperature condition of the reference low pressure (Ps), and the detected sum of indoor / outdoor temperatures (Tin '/ Tout'). Calculating (S30); Calculating a target low pressure (Pt) through a sum of the factor (F) and the reference low pressure (Ps) (S40); And controlling the low pressure of the indoor heat exchanger 51 by inputting the target low pressure Pt calculated in the control unit (S50).

And the indoor heat exchanger pressure control method of the air conditioner according to the second aspect of the present invention comprises the steps of receiving a pre-stored reference high pressure (Pd) (S110); Sensing the indoor / outdoor temperature through the temperature sensors 55 and 25 installed in the indoor unit and the outdoor unit and receiving the sensed indoor / outdoor temperature (Tin / Tout) (S120); Factor (FF) is determined by the ratio of the sum of the indoor / outdoor temperature (Tin / Tout) which is the temperature condition of the reference high pressure (Pd) and the sum of the sensed indoor / outdoor temperature (Tin '/ Tout'). Calculating (S130); Calculating a target high pressure (Ptt) by multiplying the factor (FF) by the reference high pressure (Pd) (S140); It characterized in that it comprises a step (S150) of controlling the high pressure of the indoor heat exchanger 51 in accordance with the target high pressure (Ptt) by inputting the target high pressure (Ptt) calculated in the control unit.

In the method for calculating the target pressure of the indoor heat exchanger of the air conditioner according to the third aspect of the present invention, the pre-stored reference pressure Ps is set such that the pressure of the indoor heat exchanger is reset according to the indoor / outdoor temperature (Tin '/ Tout'). Receiving (Pd); Detecting the indoor / outdoor temperature (Tin '/ Tout') through a temperature sensor installed in the indoor unit and the outdoor unit and receiving the detected indoor / outdoor temperature (Tin '/ Tout'); Computing the factor (F) (FF) by comparing the indoor / outdoor temperature (Tin / Tout) which is the temperature condition of the reference pressure (Ps) (Pd) and the sensed indoor / outdoor temperature (Tin '/ Tout') Step S30; And calculating (S40) a target pressure (Pt) (Ptt) by subtracting the ratio by the factor (F) (FF) to the reference pressure (Ps) (Pd).

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

1 is a schematic perspective view of a multi-type air conditioner according to a first embodiment of the present invention, Figure 2 is a block diagram showing an outdoor unit of a multi-type air conditioner according to a first embodiment of the present invention, Figure 3 4 is a flowchart illustrating a method for controlling an indoor heat exchanger pressure when cooling a multi-type air conditioner according to a first embodiment of the present invention, and FIG. 4 is an indoor heat exchanger when heating a multi-type air conditioner according to a second embodiment of the present invention. A pressure control method is shown in the flowchart.

As shown in FIG. 1 or 2, the multi-type air conditioner according to the present invention includes a plurality of indoor units 11, 12, 13, 14 installed in the interior of a building, and the indoor units 11, 12. And an outdoor unit (21) 22 connected to (13) (14), and the indoor unit (11) (12) (13) (14) and the outdoor unit (21) (22) are refrigerant pipes (30) ( 40, the outdoor unit 21, 22 is driven by the request of at least one of the indoor unit 11, 12, 13, 14, the indoor unit 11, 12 ( As the cooling / heating capacity required in 13) and 14 increases, the operating number of the outdoor units 21 and 22 and the operating number of compressors installed in the outdoor units 21 and 22 increase.

Here, the indoor units 11, 12, 13, and 14 are indoor heat exchangers 51 for exchanging refrigerant and indoor air, and indoor blowers installed near the indoor heat exchangers 51 to circulate indoor air. 52 and an indoor expansion valve 54 for expanding the refrigerant flowing to the indoor heat exchanger 51 when cooling.

As illustrated in FIG. 2, the outdoor units 21 and 22 receive and compress the accumulator 61 extracting only the gas refrigerant from the refrigerant supplied from the indoor unit and the gas refrigerant extracted from the accumulator 61. The compressor 62 and 63, the four-way valve 65 connected to the compressors 62 and 63 to select a compressed flow path of the refrigerant, and the refrigerant supplied from the four-way valve 65 and the outdoor air are heat exchanged. It is configured to include an outdoor heat exchanger (70).

Here, the compressors 62 and 63 are composed of an inverter compressor 62 capable of varying the compression capacity of the refrigerant, and a constant speed compressor 63 having a constant compression capacity of the refrigerant. An oil separator 64 is installed in the pipe connecting the four-way valve 65, and the oil separator 64 is connected to the suction side of the compressor 62 and 63.

In particular, the oil separator 64 separates oil from the refrigerant discharged from the compressors 62 and 63, and supplies the separated oil to the compressors 62 and 63 to supply the compressors 62 and 63. Maintain an appropriate amount of oil inside. And the suction side pipe of the oil separator 64 and the compressor 62, 63 is connected through a capillary tube 66, the oil is moved through the capillary tube 66.

The refrigerant pipe 30 for guiding the refrigerant discharged from the outdoor heat exchanger 70 to the indoor heat exchanger 51 includes electromagnetic expansion valves lev and 74 for expanding the refrigerant upon heating, and the indoor heat exchange during cooling. Sub-cooling device 80 for cooling the refrigerant moved to the machine 51, and a liquid injection device 90 for lowering the temperature of the compressor (62, 63) is provided.

Here, the outdoor electromagnetic expansion valve 74 is fully open during cooling to allow the refrigerant condensed in the outdoor heat exchanger to pass through without expansion, but when heated, the outdoor electromagnetic expansion valve 74 is opened to a predetermined size to convey the refrigerant condensed in the indoor heat exchanger 51. Before entering the outdoor heat exchanger 70 is expanded to a liquid in a spray state.

And the supercooling device 80 is a subcooler 82 is installed to surround a portion of the refrigerant pipe 30 and the refrigerant pipe 30 connected to the indoor heat exchanger 51 through the subcooler 82. ") Connected to the bypass pipe 84 to bypass some of the refrigerant moving in the refrigerant pipe 30 into the subcooler 82, and the electronic expansion is installed in the bypass pipe 84 And a valve 86 and a recovery pipe 87 for connecting the subcooler 82 and the refrigerant pipe 61 'on the input side of the accumulator 61.

On the other hand, in order to sense the temperature of the refrigerant flowing in / out of the supercooling device 50, the discharge side refrigerant pipe (30 ") of the subcooler 30 and the electronic expansion valve in the bypass pipe (84) The temperature of the refrigerant is measured in the bypass pipe 86 " installed on the discharge side of the valve 86 and the pipe 87 'provided between the subcooler 82 and the valve 89 in the recovery pipe 87. Temperature sensors 101, 102 and 103 are provided.

In addition, the discharge side refrigerant pipes of the compressors 62 and 63 are provided with temperature sensors 104 and 105 for sensing the temperature of the refrigerant discharged from the compressors 62 and 63 and the accumulator 61. The temperature sensor 106 for sensing the temperature of the refrigerant flowing into the accumulator 61 is also installed at the input side refrigerant pipe 61 ′.

On the other hand, the refrigerant pipe (30 ") is provided with a dryer (110) for removing moisture in the refrigerant pipe (30"), the refrigerant passing through the dryer 110 is a by-pass in the refrigerant pipe (30 ") Passed and flow to the indoor heat exchanger (51) side.

Hereinafter, a method for controlling pressure of an indoor heat exchanger of a multi-type air conditioner according to the present invention will be described in more detail with reference to FIG. 3 or FIG. 4.

First, in the cooling operation of the multi-type air conditioner according to the present invention, the pressure control method of the indoor heat exchanger may include receiving a pre-stored reference low pressure (Ps) as shown in FIG. 3 and an indoor unit and an outdoor unit. Receiving the indoor / outdoor temperature through the installed temperature sensor (55, 25) and receiving the detected indoor / outdoor temperature (S20), and the indoor / outdoor temperature that is the temperature condition of the reference low pressure (Ps) Calculating a factor F through a difference between a sum of Tin / Tout and the detected sum of indoor / outdoor temperatures Tin '/ Tout' (S30), the factor F and the Computing a target low pressure (Pt) through the sum of the reference low pressure (Ps) (S40), and inputs the calculated target low pressure (Pt) to the control unit according to the target low pressure (Pt) the indoor heat exchanger ( And controlling the low pressure of 51).

Here, the reference low pressure input step (S10) is a value previously input to the controller through an experiment, and the reference low pressure (Ps) is a low pressure of the indoor heat exchanger 51 set based on the average temperature of the region where the product is shipped. The cooling cycle of the air conditioner generates maximum efficiency when the indoor heat exchanger 51 is formed at the reference low pressure Ps at the reference temperature Tin / Tout.

And the temperature receiving step (S20) detects the indoor / outdoor temperature through the temperature sensor 55, 25 installed in the indoor unit 11 and the outdoor unit 21, the detection temperature (Tin '/ Tout') is Received by the controller.

In addition, the low pressure of the indoor heat exchanger (51) is sensed by the pressure sensor (107) installed in the refrigerant pipe (61 ') input side of the accumulator (61).

And the calculation formula of the factor calculation step (S30) is

F = (Tin '+ Tout')-(Tin + Tout)

The factor F calculated in the factor calculation step S30 has a positive value or a negative value depending on indoor / outdoor temperature conditions.

And the calculation formula of the target low pressure (Pt) calculation step (S40) is

Pt = Ps + (F * α)

Is the proportional constant obtained by experiment.

Thus, the target low pressure Pt is varied by a factor F, which is a variable, and when the detection temperature Tin '/ Tout' is greater than the sum of the reference temperature Tin / Tout, the target low pressure Pt Is increased, and the value of the target low pressure Pt is decreased when the sum of the sensing temperatures Tin '/ Tout' is smaller than the sum of the reference temperatures Tin / Tout.

That is, when operated in a cooling cycle, the room is maintained at a constant temperature by the indoor unit 11, and when the outdoor temperature Tout 'rises, the value of the target low pressure Pt increases, and the outdoor temperature Tout' When () decreases, the value of the said target low pressure Pt becomes small.

Thereafter, the calculated target low pressure Pt is input to the controller, and the controller controls the outdoor unit 21 according to the target low pressure Pt instead of the reference low pressure Ps. (S50)

Thus, when the pressure of the refrigerant sensed at the inlet side of the accumulator 61 is lower than the target low pressure Pt, the compressor 62 and 63 are controlled to increase the sensed pressure to the target low pressure Pt. When the sensed pressure exceeds the target low pressure Pt, the compressors 62 and 63 are controlled to lower the sensed pressure to the target low pressure Pt.

In the indoor heat exchanger pressure control method of the multi-type air conditioner according to the present invention, after the target low pressure control step (S50), the indoor / outdoor temperature (Tin "/ Tout") is sensed again (S60). It further comprises a step (S70) for comparing with the temperature (Tin '/ Tout') of S20.

Therefore, when the indoor / outdoor temperature Tin '/ Tout' (Tin "/ Tout") compared in the temperature comparison step S70 is changed, it is returned to the factor calculation step S30, and the indoor / outdoor temperature Tin '/ Tout') is not changed, and after checking the stop condition of the air conditioner (S80), it is returned to the target low pressure control step (S50).

Here, more preferably, the detection temperature Tin '/ Tout' and the re-sensing temperature Tin "/ Tout" compared in the temperature comparison step S70 are the target low pressure control step S50 when the difference is more than a predetermined range. ).

In the stop condition checking step S80, when the air conditioner is the stop condition, the cooling operation is stopped. Otherwise, the air conditioner is returned to the target low pressure control step S50.

As described above, the present invention can improve efficiency because the reference low pressure of the indoor heat exchanger 51 is updated to the target low pressure Pt according to the indoor / outdoor temperature Tin '/ Tout' during cooling.

Next, the indoor heat exchanger pressure control method when heating the multi-type air conditioner according to the present invention, as shown in Figure 4, receiving the pre-stored reference high pressure (Pd) (S110), and installed in the indoor unit and outdoor unit Receiving the indoor / outdoor temperature through the temperature sensor 55, 25 and receiving the detected indoor / outdoor temperature (S120), and the indoor / outdoor temperature (Tin) that is the temperature condition of the reference high pressure (Pd) / Tout) and calculating a factor (FF) through a ratio of the sum of the detected indoor / outdoor temperature (Tin '/ Tout') (S130), the factor (FF) and the reference Computing the target high pressure (Ptt) by multiplying the high pressure (Pd) (S140), and inputs the target high pressure (Ptt) calculated in the control unit of the indoor heat exchanger 51 according to the target high pressure (Ptt) It is configured to include a step of controlling the high pressure (S150).

Here, when the multi-type air conditioner is driven by a heating cycle, the refrigerant compressed by the compressors (62) (63) is moved to the indoor heat exchanger (51) via a four-way valve (65), and the indoor heat exchanger (51). The high pressure is formed inside the compressed refrigerant.

The reference high pressure Pd is a value input to the controller at the time of factory shipment and is a pressure value obtained by an experiment based on the reference temperature Tin / Tout.

Wherein the calculation formula of the factor calculation step (S140) is different from the first embodiment

Factor (FF) = (Tin '+ Tout') / (Tin + Tout)

Is made of.

And the calculation formula of the target high pressure calculation step (S140)

Ptt = Pd * ABS (FF) * β

The ABS (FF) is the absolute value of the factor (FF) calculated by the factor calculation step (S140), and the 'β' is a proportional constant obtained by the experiment.

Thus, the target high pressure Ptt calculated by the above process is input to the controller to replace the reference high pressure Pd, and the controller controls the outdoor unit 21 according to the target high pressure Ptt.

Hereinafter, since the remaining steps of the second embodiment are the same as the first embodiment, detailed description thereof will be omitted.

On the other hand, the above embodiments are described by taking a multi-type air conditioner as an example, but may be applied to all of the general air conditioner.

Therefore, the indoor heat exchanger pressure control method of the multi-type air conditioner according to the present invention sets the target pressure of the indoor heat exchanger according to the indoor / outdoor temperature change, and adjusts the pressure of the indoor heat exchanger according to the target pressure. There is an effect of improving the efficiency of the group.

In addition, the indoor heat exchanger pressure control method of the multi-type air conditioner according to the present invention has an effect of properly calculating the target pressure according to the indoor / outdoor temperature by calculating factor values using different equations according to cooling / heating operations. have.

In addition, the indoor heat exchanger pressure control method of the multi-type air conditioner according to the present invention has an effect of rapidly performing cooling / heating because the target pressure of the indoor heat exchanger is replaced with the target pressure instead of the initial reference pressure in the overload condition.

Claims (9)

Receiving a pre-stored reference low pressure Ps (S10); Sensing the indoor / outdoor temperature through the temperature sensors 55 and 25 installed in the indoor unit and the outdoor unit and receiving the detected indoor / outdoor temperature Tin '/ Tout' (S20); Factor (F) is determined by the difference between the sum of indoor / outdoor temperatures (Tin / Tout), the temperature condition of the reference low pressure (Ps), and the detected sum of indoor / outdoor temperatures (Tin '/ Tout'). Calculating (S30); Calculating a target low pressure (Pt) through a sum of the factor (F) and the reference low pressure (Ps) (S40); And controlling the low pressure of the indoor heat exchanger (51) by inputting the target low pressure (Pt) calculated in the control unit (S50). The method according to claim 1, The calculation formula of the factor calculation step (S30) is F = (Tin '+ Tout')-(Tin + Tout) Indoor heat exchanger pressure control method of an air conditioner, characterized in that. The method according to claim 2, The calculation formula of the target low pressure calculation step (S40) is Pt = Ps + (F * α) And α is a proportional constant obtained by an experiment. The method according to claim 1, After the target low pressure control step S50, the indoor / outdoor temperature is redetected (S60), and the change between the redetected indoor / outdoor temperature and the indoor / outdoor temperature of the step S20 is received. If it occurs, the indoor heat exchanger pressure control method of the air conditioner, characterized in that returned to the step before the factor calculation step (S30). Receiving a pre-stored reference high pressure (Pd) (S110); Sensing the indoor / outdoor temperature through the temperature sensors 55 and 25 installed in the indoor unit and the outdoor unit and receiving the sensed indoor / outdoor temperature (Tin / Tout) (S120); Factor (FF) is determined by the ratio of the sum of the indoor / outdoor temperature (Tin / Tout) which is the temperature condition of the reference high pressure (Pd) and the sum of the sensed indoor / outdoor temperature (Tin '/ Tout'). Calculating (S130); Calculating a target high pressure (Ptt) by multiplying the factor (FF) by the reference high pressure (Pd) (S140); Controlling the high pressure of the indoor heat exchanger (51) according to the target high pressure (Ptt) by inputting the target high pressure (Ptt) calculated in the controller (S150). Way. The method according to claim 5, The calculation formula of the factor calculation step (S130) is FF = (Tin '+ Tout') / (Tin + Tout) Indoor heat exchanger pressure control method of an air conditioner, characterized in that. The method according to claim 6, The calculation formula of the target high pressure calculation step (S140) Ptt = Pd * ABS (FF) * β Wherein, 'β' is a proportional constant obtained by experiments, the indoor heat exchanger pressure control method of the air conditioner. The method according to claim 5, After the target high pressure control step (S150), the indoor / outdoor temperature is redetected (S60), and a change between the redetected indoor / outdoor temperature and the indoor / outdoor temperature of receiving the temperature (S120) is determined. If it occurs, the pressure control method of the indoor heat exchanger of the air conditioner, characterized in that returned to the step before the factor calculation step (S130). In order to reset the pressure of the indoor heat exchanger according to the indoor / outdoor temperature (Tin '/ Tout'), Receiving a pre-stored reference pressure (Ps) (Pd); Detecting the indoor / outdoor temperature (Tin '/ Tout') through a temperature sensor installed in the indoor unit and the outdoor unit and receiving the detected indoor / outdoor temperature (Tin '/ Tout'); Computing the factor (F) (FF) by comparing the indoor / outdoor temperature (Tin / Tout) which is the temperature condition of the reference pressure (Ps) (Pd) and the sensed indoor / outdoor temperature (Tin '/ Tout') Step S30; An indoor heat exchanger target of the air conditioner including a step (S40) of calculating a target pressure Pt (Ptt) by subtracting the ratio by the factor (F) (FF) to the reference pressure (Ps) (Pd). Pressure calculation method.

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