KR101176635B1 - Multi air conditioner capable of heating and cooling simultaneously and control method thereof - Google Patents

Abstract

The present invention relates to a simultaneous air-conditioning-type multi air conditioner and a control method thereof, and an object of the present invention is to prevent excessive operation of a compressor during heating main operation, to prevent congestion of refrigerant in an outdoor heat exchanger, and to freeze it in an indoor heat exchanger. The present invention provides a simultaneous air-conditioning type multi air conditioner and a control method thereof.

To this end, the simultaneous air-conditioning-type multi air conditioner according to the present invention includes a high pressure gas pipe, a low pressure gas pipe, and a liquid pipe connected between at least one outdoor unit and a plurality of air conditioning conversion sets; A flow control valve installed in the bypass pipe connecting the high pressure gas pipe and the liquid pipe; And a control unit for increasing the opening degree of the flow rate control valve when the heating rate is not lower than or equal to the reference ratio and the cooling requirement of the cooling chamber is lower than or equal to the reference requirement.

Multi air conditioner, simultaneous air conditioning and heating operation

Description

MULTI AIR CONDITIONER CAPABLE OF HEATING AND COOLING SIMULTANEOUSLY AND CONTROL METHOD THEREOF}

1 is a flow chart showing a simultaneous air-conditioning type multi air conditioner according to an embodiment of the present invention.

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

3A to 3C are flowcharts illustrating a control procedure of a simultaneous air-conditioning type multi air conditioner according to an embodiment of the present invention.

Figure 4 is a view showing a flow path state during the heating operation of the simultaneous air-conditioning multi-air conditioner according to an embodiment of the present invention.

Description of the Related Art [0002]

200: outdoor unit 210: compressor

220: outdoor heat exchanger 230: four-way valve

250: bypass pipe 260: flow control valve

270: shut-off valve 280: outdoor electric expansion valve

290: outdoor blowing fan 300: indoor unit

301: temperature sensor in the heating room 302: indoor heat exchanger

304: indoor electric expansion valve 400: air conditioning switch

440: air conditioning switch 520: outdoor temperature sensor

530: low pressure sensor

The present invention relates to a simultaneous air-conditioning multi air conditioner and a control method thereof, and more particularly, to prevent excessive operation of a compressor during a heating main operation, to prevent congestion of refrigerant in an outdoor heat exchanger, and to freeze it in an indoor heat exchanger. The present invention relates to a simultaneous air-conditioning type multi air conditioner and a control method thereof.

In general, an air conditioner is a device for cooling or heating a room using a refrigeration cycle. Recently, a multi-type air conditioner including a single outdoor unit and a plurality of indoor units respectively installed in a plurality of rooms has been released.

However, even in the case where a cooling operation is required in some rooms and a heating operation is required in some rooms, such a multi-air conditioner has a limitation that does not adequately respond to the requirements of each room by performing a cooling operation or a heating operation uniformly. have.

In order to overcome this limitation, recently, simultaneous air-conditioning and multi-air conditioners have been introduced, which allow indoor units installed in some rooms to perform heating operation and indoor units installed in other rooms to perform cooling operation. have.

Simultaneous air-conditioning-type multi air conditioner operates a heating main with a large heating capacity ratio, and the high-pressure gaseous refrigerant compressed by the compressor flows into the air-conditioning conversion unit through the high-pressure gas pipe. The high-pressure gas refrigerant flowing into the air-conditioning conversion unit flows into the heat exchanger of the heating chamber in which the heating valve is opened. Thus, the high-pressure gas refrigerant flowing into the heat exchanger in the heating chamber is discharged by changing into a liquid state while exchanging heat with the indoor air. Some of the liquid refrigerant discharged from the heating chamber flows to the outdoor unit along the liquid pipe and the other flows to the cooling chamber which performs the cooling operation.

However, when the heating main body operation is performed in this way, the liquid refrigerant flows excessively toward the outdoor unit and the amount of the liquid refrigerant flowing into the cooling chamber is insufficient, resulting in a decrease in the cooling capacity of the cooling chamber.

In order to solve the above problems, as disclosed in Korean Patent Laid-Open Publication No. 2005-0005089, a simultaneous air-conditioning type multi air conditioner including a bypass pipe connecting a high pressure gas pipe and a liquid pipe has been proposed.

When the conventional simultaneous air-conditioning type multi-air conditioner disclosed in the above publication performs the heating main operation, a part of the high-pressure gas refrigerant flowing through the high-pressure gas pipe is introduced into the liquid pipe through the bypass pipe to suppress the refrigerant flowing toward the outdoor heat exchanger. Therefore, the cooling capacity of the cooling chamber is increased by increasing the amount of refrigerant flowing to the cooling chamber.

However, the conventional multi-type air conditioner capable of simultaneous air-conditioning operation lowers the pressure inside the high pressure gas pipe by sending a part of the refrigerant flowing through the high pressure gas pipe to the liquid pipe. In order to compensate for this, the compressor has a large compression capacity, thereby increasing power consumption and decreasing efficiency of a conventional simultaneous air-conditioning multi-air conditioner.

In the conventional simultaneous air-conditioning multi air conditioner, even when the outdoor temperature is low, the outdoor heat exchanger is used as an evaporator, and the pressure inside the outdoor heat exchanger is lowered. In addition, the pressure inside the low pressure gas pipe connected to the outdoor heat exchanger and the pressure inside the indoor heat exchanger connected to the low pressure gas pipe are lowered. Accordingly, the refrigerant temperature of the indoor heat exchanger is lowered, so that dew freezing on the indoor heat exchanger freezes.

Accordingly, the present invention has been proposed to solve the above-mentioned problems, and an object of the present invention is to prevent excessive operation of the high-pressure gas refrigerant into the liquid pipe during the heating main body operation, thereby preventing excessive operation of the compressor to consume power consumption. It is an object of the present invention to provide a simultaneous air-conditioning type multi air conditioner and a control method for reducing the cost.

Simultaneous air-conditioning-type multi-air conditioner prevents the outdoor heat exchanger from being used as an evaporator when the outdoor temperature is low and prevents the saturation pressure of the outdoor heat exchanger from being lower than the pressure inside the low pressure gas pipe. To prevent the liquid from stagnating and stagnating, and to prevent the internal pressure of the outdoor heat exchanger from being excessively lowered, thereby providing a simultaneous air-conditioning type multi-air conditioner and a control method thereof. For that purpose.

Simultaneous cooling and heating multi air conditioner according to the present invention for achieving the above object is a high-pressure gas pipe, a low-pressure gas pipe and a liquid pipe connected between at least one outdoor unit and a plurality of air-conditioning conversion set; A flow control valve installed in the bypass pipe connecting the high pressure gas pipe and the liquid pipe; And a control unit for increasing the opening degree of the flow rate control valve when the heating rate is not lower than or equal to the reference ratio and the cooling requirement of the cooling chamber is lower than or equal to the reference requirement.

The apparatus may further include an outdoor expansion valve and an outdoor blowing fan, wherein the control unit performs superheat control using the outdoor expansion valve and low pressure control using the outdoor blowing fan, and controls the average opening degree of the cooling chamber. According to the adjustment of the opening degree of the flow control valve.

In another aspect, the simultaneous air-conditioning multi-air conditioner according to the present invention for achieving the above object is an outdoor temperature sensor for sensing the outdoor temperature; Low pressure sensor for detecting the pressure inside the low pressure gas pipe; The saturation pressure of the outdoor heat exchanger is calculated using the outdoor temperature detected by the outdoor temperature sensor, and the refrigerant retention pressure is calculated by using the pressure sensed by the low pressure sensor, and the cooling and heating ability is improved by comparing the saturation pressure with the refrigerant retention pressure. It includes a control unit for the operation or operation to prevent refrigerant retention.

Here, the high-pressure gas pipe and the liquid pipe is installed in the bypass pipe flow control valve for controlling the flow rate and the shut-off valve for blocking the refrigerant moving to the outdoor heat exchanger side and the outdoor blower fan further, the control unit is air-conditioning A simultaneous air-conditioning type multi-air conditioner which cuts off the flow regulating valve and the shut-off valve and stops the outdoor blower fan when performing the performance enhancing operation.

And a flow control valve installed at a bypass pipe connecting the high pressure gas pipe and the liquid pipe, a shutoff valve for blocking the refrigerant moving to the outdoor heat exchanger side, and an outdoor blower fan. When performing the preventive operation, open the flow regulating valve and the shutoff valve, stop the outdoor blower fan, detect the low pressure again, and if the detected low pressure is not greater than the cooling capacity optimization pressure, open the opening of the outdoor electric expansion valve. If the sensed low pressure is greater than the cooling capacity optimization pressure, the opening degree of the outdoor electric expansion valve is decreased.

In another aspect, the control method of the simultaneous air-conditioning-type multi-air conditioner according to the present invention for achieving the above object is to determine whether the heating capacity ratio is more than the reference ratio during the heating main operation, the heating capacity ratio is less than the standard ratio Otherwise, the flow rate of the high pressure gas flowing into the liquid pipe from the high pressure gas pipe is adjusted.

Here, the flow rate control is performed by controlling the opening degree of the outdoor motor expansion valve while controlling the superheat degree and the low pressure control and the shutoff valve using the air volume control of the outdoor blowing fan.

The flow rate adjustment calculates an average opening of the indoor electric expansion valve of the cooling chamber, decreases the flow rate if the calculated average opening is not larger than the reference opening, and increases the flow rate if the calculated average opening is larger than the reference opening.

In another aspect, the control method of the simultaneous air-conditioning-type multi air conditioner according to the present invention for achieving the above object is to determine whether the heating capacity ratio is more than the reference ratio during the heating main operation, the heating capacity ratio is the reference If the ratio is smaller than the ratio, the saturation pressure of the outdoor heat exchanger is less than the refrigerant stagnation pressure of the low pressure gas pipe. The refrigerant stagnation prevention operation is performed. If the saturation pressure of the outdoor heat exchanger is not less than the refrigerant stagnation pressure of the low pressure gas pipe, the cooling and heating ability Ensure secure operation.

Here, the cooling and heating capacity securing operation closes the flow control valve and the shutoff valve, stops the outdoor blower fan, calculates the average outlet temperature of the heating chamber, and if the average outlet temperature of the heating chamber is less than the optimum temperature, If the opening degree is increased and the average outlet temperature of the heating chamber is not smaller than the optimum temperature, the opening degree of the flow control valve is decreased.

The refrigerant stagnation prevention operation opens the flow control valve and the shutoff valve and stops the outdoor blower fan. When the low pressure of the low pressure gas pipe is greater than the cooling capacity optimum pressure, the opening degree of the outdoor electric expansion valve is reduced and the low pressure of the low pressure gas pipe is reduced. If the cooling capacity is not greater than the optimum pressure, the opening degree of the outdoor electric expansion valve is reduced.

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

1 and 2, the simultaneous air-conditioning type multi-air conditioner 100 according to an embodiment of the present invention is an outdoor unit 200 is installed outdoors, a plurality of indoor units 300 are installed indoors, A plurality of indoor unit 300 includes a control unit 500 for the overall control of the air-conditioning conversion unit 400 and the simultaneous air-conditioning-type multi-air conditioner 100 to enable the cooling operation or heating operation.

The outdoor unit 200 includes a compressor 210 for compressing a refrigerant, an outdoor heat exchanger 220 for exchanging refrigerant with outdoor air, and a heating or cooling cycle according to an operation mode of the simultaneous air-conditioning-type multi air conditioner 100. Four-way valve 230 to be set, the accumulator 201 provided on the suction side of the compressor 210, the low-pressure gas pipe 430 for providing a flow path for the low-pressure gas refrigerant flows into the accumulator 201, The outdoor motor expansion valve 280 connected to one side of the outdoor heat exchanger 220, the first connection pipe 213 connecting the other side of the outdoor heat exchanger 220 and the four-way valve 230, and the four-way valve 230. ) And a second connecting pipe 214 connecting the accumulator 201, a third connecting pipe 215 connecting the outdoor heat exchanger 220 and the outdoor electric expansion valve 280, and an outdoor electric expansion valve 280. ) And the receiver tank 202 installed between the liquid pipe 420 and the four-way valve 230 are connected to the four-way valve 230. High-pressure gas pipe 410 to move the excess high-pressure gas refrigerant to the refrigerant conversion unit 400, high-pressure branch pipe 204 for connecting the first connecting pipe 213 and the high-pressure gas pipe 410, and high-pressure gas pipe 410 It includes a bypass pipe 250 to bypass a portion of the high pressure gas to the liquid pipe (420).

Compressor 210 is composed of a constant speed compressor 211 and a variable compressor 212 in order to correspond to the variable capacity of the simultaneous air-conditioning type multi air conditioner (100).

The compressor 210 inhales low pressure gas refrigerant from some or all of the low pressure gas pipe 430 and the outdoor heat exchanger 220 according to the operation mode of the simultaneous air-conditioning-type multi air conditioner 100, compresses the low pressure gas refrigerant to high pressure, and then compresses the high pressure. The high pressure gas refrigerant is provided to some or all of the gas pipe 410 and the outdoor heat exchanger 220. The constant speed compressor 210 is operated according to a constant compression capacity, the variable compressor 212 is operated according to the variable compression capacity by the control of the control unit 500.

An accumulator 201 is installed on the suction side of the compressor 220 to allow the refrigerant in the gas state to flow into the compressor 220 to ensure reliability of the compressor 210.

In other words, the accumulator 201 temporarily stores the liquid refrigerant in the refrigerant flowing through the low pressure gas pipe 430 toward the compressor 220 and the liquid refrigerant in the refrigerant flowing through the second connecting pipe 214 temporarily. After the change to the refrigerant in the gas phase to be introduced into the compressor (210). Accordingly, the compressor 210 operates reliably by receiving only gaseous refrigerant.

At the suction port side of the compressor 210, a low pressure sensor 270 for detecting a pressure inside the low pressure gas pipe 430 is installed. The low pressure sensor 270 senses the pressure inside the low pressure gas pipe 430 and provides the control unit 500 with a low pressure that is an internal pressure value of the low pressure gas pipe 430.

The outdoor heat exchanger 220 includes a plurality of heat exchange fins and a refrigerant pipe 221. One end of the refrigerant pipe 221 is connected to the first connection pipe 213 and the other end of the refrigerant pipe 221 is connected to the outdoor electric expansion valve 280.

At an adjacent position of the outdoor heat exchanger 220, an outdoor blower fan 290 is installed to forcibly blow outdoor air to the outdoor heat exchanger 220. The outdoor blower fan 290 is controlled by the control unit 500, the blowing amount or on / off.

The first connecting pipe 213 is connected to the second port 230B of the four-way valve 230. The high pressure branch pipe 204 is branched from the first connection pipe 213 to the high pressure gas pipe 410, and a high pressure branch valve 205 is installed on the high pressure branch pipe 204. The check valve 206 is installed on the high pressure gas pipe 410 side of the high pressure branch valve 205 so that the moving direction of the fluid flowing inside the high pressure branch pipe 204 has one direction. The high pressure branch pipe valve 205 is opened when the simultaneous air-conditioning-type multi-air conditioner 100 is operated in a cooling main body so that a part of the high pressure gas discharged from the compressor 210 is introduced into the high pressure gas pipe 410. .

The valve 207 connected in parallel with the outdoor electric expansion valve 280 allows the flow of the refrigerant flowing out of the outdoor heat exchanger 220 to be selectively.

The receiver tank 202 is installed at the portion where the outdoor electric expansion valve 280 and the liquid pipe 420 are connected to each other so that the amount of refrigerant flowing into the outdoor heat exchanger 220 is constant so that the simultaneous air-conditioning-type multi-air conditioner 100 is provided. ) To ensure reliability.

A shutoff valve 270 is installed at a portion adjacent to the receiver tank 202 among the portions where the receiver tank 202 and the liquid pipe 420 are connected.

The bypass pipe 250 is connected to the liquid pipe 420 on the opposite side of the receiver tank 202 based on the shutoff valve 270. And on the bypass pipe 250 is provided with a flow rate control valve 260 for adjusting the flow rate of the refrigerant flowing through the bypass pipe 250. When the simultaneous air-conditioning-type multi-air conditioner 100 performs the heating main operation, if the flow control valve 260 is opened, the refrigerant discharged from the indoor unit 300 performing the heating operation performs the cooling operation. It is possible to flow toward to improve the cooling capacity of the indoor unit 300 to perform the cooling operation.

The four-way valve 230 includes a first port 230A, a second port 230B, a third port 230C, and a fourth port 230D. The four-way valve 230 is controlled by the control unit 500 to allow the compressor 210, the outdoor heat exchanger 220, and the indoor heat exchanger 302 to form a heating cycle or a cooling cycle. In other words, in order to form a cooling refrigerant cycle, the four-way valve 230 is controlled by the control unit 500 to connect the first port 230A and the second port 230B. Accordingly, the refrigerant circulates through the compressor 210-> outdoor heat exchanger 220-> indoor electric expansion valve 304-> indoor heat exchanger 302-> compressor 210. In addition, the four-way valve 230 is controlled by the controller 500 so that the heating refrigerant cycle is formed, and the first port 230A and the fourth port 230D are connected to each other. Accordingly, the refrigerant circulates through the compressor 210-> indoor heat exchanger 302-> outdoor electric expansion valve 280-> outdoor heat exchanger 220-> compressor 210.

An outdoor temperature sensor 520 for detecting an outdoor temperature is installed at an inner side of the outdoor unit 200. The outdoor temperature sensor 520 detects the outdoor temperature and provides an outdoor temperature value to the controller 500.

Air conditioning unit 400 is a plurality of heating and cooling conversion set 440 consisting of a heating valve 441 and the cooling valve 442, the first high-pressure gas branch pipe 412 branched from the high-pressure gas pipe 410, and low pressure And a first low pressure gas branch pipe 432 branched from the gas pipe 430 and a first liquid branch pipe 422 branched from the liquid pipe 420.

Branched from the second high pressure gas branch pipe 413 branched from the first high pressure gas pipe 412 and the second liquid branch pipe 423 and the first low pressure gas branch pipe 432 branched from the first liquid branch pipe 422. A second low pressure gas branch pipe 433 is further included.

The heating valve 441 of the cooling and heating conversion set 440 is connected to the second high pressure gas branch pipe 413, and the cooling valve 442 of the cooling and heating conversion set 440 is connected to the second low pressure gas branch pipe 433. . The heating valve 441 and the cooling valve 442 are connected to the indoor connection pipe 305, and the indoor connection pipe 305 is connected to one side of the indoor heat exchanger 302. And the second liquid branch pipe 423 is connected to the indoor electric expansion valve 304 of the indoor unit 300 to be described later.

The cooling and heating conversion unit 400 allows each indoor unit 300 to perform a heating or cooling operation. In other words, when any one indoor unit 300 performs the heating operation, the heating valve 441 is opened and the cooling valve 442 is closed so that the refrigerant flowing through the second high pressure gas branch pipe 413 is an indoor heat exchanger. After entering and condensing 302, the second liquid branch pipe 423 may flow along. When any one indoor unit 300 performs the cooling operation, the heating valve 441 is closed and the cooling valve 442 is opened so that the liquid refrigerant flowing through the second liquid branch pipe 423 is transferred to the indoor heat exchanger 302. After being introduced and evaporated, it can flow along the second low pressure gas pipe 433.

The indoor unit 300 is an indoor electric expansion valve 304 installed at a portion connected to the indoor heat exchanger 302, the indoor heat exchanger 302, and the second liquid branch pipe 423 to allow the indoor air and the refrigerant to exchange heat. And the indoor heat exchanger 302 and the indoor electric expansion valve 304 is installed in the portion connected to the heating chamber exit side temperature sensor 301 for detecting the temperature of the refrigerant.

Here, the heating chamber is defined as an indoor unit that performs the heating operation of the indoor unit 300.

The indoor unit 300 is composed of a plurality, each indoor unit 300 is installed in each room or room, heating or cooling each room or room.

The controller 500 performs overall control of the simultaneous air-conditioning type multi air conditioner 100. On the input side of the control unit 500, an outdoor temperature sensor 520, a low pressure sensor 530, a heating indoor unit outlet side temperature sensor 301, and an input unit 510 for allowing a user to input a control command are provided. On the output side of the control unit 500, a compressor driver 540 for driving the compressor 210, a four-way valve driver 550 for driving the four-way valve 230, and a flow control valve 260 for driving the four-way valve 230 are provided. A flow rate control valve driver 560, a shutoff valve driver 570 for driving the shutoff valve 270 for driving the shutoff valve 270, and an air conditioning and heating driver 580 for driving the air conditioning switch 440. An outdoor expansion valve driver 590 for driving the outdoor motor expansion valve 280 and an indoor expansion valve driver 595 for driving the indoor expansion valve 304 are included.

Hereinafter, a control method and an operation of a simultaneous air-conditioning type multi air conditioner according to an embodiment of the present invention will be described with reference to the accompanying drawings.

3A to 3C and 4, first, when power is applied to the simultaneous air-conditioning-type multi air conditioner 100 (801), the controller 500 determines whether an operation start command is input (802). .

In this case, if the operation start command is not input, the controller 500 determines whether the operation start command is continuously input and calculates the heating capacity ratio when the operation start command is input (803). Here, the heating capacity ratio means a percentage of the capacity of the heating room to perform the heating operation to the operating capacity of the entire indoor unit.

Next, the control unit 500 determines whether the heating capacity ratio corresponds to the heating capacity ratio corresponding to the heating subject operation (804). Here, the heating capacity ratio corresponding to the heating main operation means approximately 50% or more and 99% or less.

At this time, if the heating capacity ratio does not correspond to the heating capacity ratio corresponding to the heating subject operation, the simultaneous air-conditioning type multi-air conditioner 100 to perform the operation corresponding to the other heating capacity ratio. Control (805). In other words, when the heating capacity is 100%, the control unit 500 controls the simultaneous air-conditioning-type multi air conditioner 100 to perform the heating operation, and when the heating capacity is about 1% or more and 49% or less, the simultaneous air-conditioning-type multi air conditioner. The machine 100 controls to perform the cooling main body operation, and when the heating capacity is 0%, the simultaneous cooling and heating type multi air conditioner 100 controls to perform the cooling operation.

Subsequently, the controller 500 determines whether the operation is a termination condition corresponding to the heating capacity ratio other than that (806). At this time, the controller 500 controls the simultaneous air-conditioning-type multi-air conditioner 100 to continuously perform the operation corresponding to the other heating capacity ratio unless the end condition of the operation corresponding to the heating capacity ratio other than that. If it is the end condition of the operation corresponding to the heating ratio other than that, it is determined whether the operation end condition (807).

At this time, the control unit 500 returns to step 803 of calculating the heating capacity ratio if it is not the operation termination condition by determining whether the operation is terminated condition, and if the operation termination condition is applied to the simultaneous air-conditioning type multi-air conditioner 100. The power is turned off and terminates (808).

On the other hand, if the heating capacity ratio is the heating capacity ratio corresponding to the heating main operation in step 804, as shown in FIG. 4, the control unit 500 closes the flow control valve 260 while simultaneously cooling and heating multi air conditioners ( In step 809, the control to perform the heating subject operation is performed. In other words, the heating valve 441 of the heating and cooling conversion set 440 corresponding to the heating chamber 300 performing the heating operation is opened and the cooling valve 442 is closed. In addition, the heating valve 441 of the cooling / heating conversion set 440 corresponding to the cooling chamber 300 performing the cooling operation is closed and the cooling valve 442 is opened. The first port 230A and the fourth port 230D of the four-way valve 230 of the outdoor unit 200 are connected, and the second port 230B and the third port 230C of the four-way valve 230 are connected. Be sure to Accordingly, the high pressure refrigerant compressed by the compressor 210 passes through the high-pressure gas pipe 410 and the heating valve 441 of the air-conditioning conversion set 440 and passes through the indoor heat exchanger 302 of the heating chamber 300. . At this time, the high-pressure refrigerant is condensed while exchanging heat with the indoor air. The refrigerant condensed while passing through the indoor heat exchanger 302 of the heating chamber 300 sequentially passes through the second liquid branch pipe 423, the first liquid branch pipe 422, and the second liquid branch pipe 423. Pass through the indoor heat exchanger 302 of the cooling chamber 300 to perform the cooling operation. At this time, the refrigerant passing through the indoor heat exchanger 302 passing through the cooling chamber 300 is evaporated while exchanging heat with the indoor air. The refrigerant evaporated while passing through the indoor heat exchanger 302 passes through the cooling valve 442 and the second and first low pressure branch pipes 433 and 432 of the air conditioning switch 440, and then passes through the low pressure gas pipe 430. Through the compressor 210 is introduced again.

In doing so, the control unit 500 determines whether the heating capacity ratio is less than the reference ratio (810).

At this time, if the heating capacity ratio is not less than the reference ratio, the control unit 500 opens the shut-off valve 270. Then, the target superheat is controlled by adjusting the opening degree of the outdoor electric expansion valve 280 and low pressure control is performed through the outdoor blower fan 290 (811).

Next, the controller 500 calculates an average opening degree by measuring the opening degree of the indoor electric expansion valve 304 of the cooling chamber 300 performing the cooling operation (812).

The controller 500 determines whether the calculated average opening degree is greater than or equal to the set opening degree (813). At this time, if the calculated average opening degree is not more than the reference opening degree, tightening the flow control valve 260 through the flow control valve 260 to reduce the flow rate of the high-pressure gas refrigerant bypassed (814), the calculated average opening degree When the flow rate is greater than or equal to the reference opening, the flow rate control valve 260 is released to allow the flow rate of the high pressure gas refrigerant bypassed through the flow rate control valve 260 to increase (815). Accordingly, the amount of refrigerant flowing into the cooling chamber 300 flows into the amount of refrigerant required by the cooling chamber 300 to improve the cooling capability of the cooling chamber 300.

Next, the control unit 500 determines whether the heating subject operation termination condition (816). At this time, if it is not the heating subject operation termination condition, the heating subject operation is performed, and if the heating subject operation termination condition is determined (807) and subsequent steps to determine whether the operation termination condition.

On the other hand, if the heating capacity ratio is less than the reference ratio in step 810 of determining whether the heating capacity ratio is below the reference ratio, the control unit 500 through the outdoor heat exchanger 220 through the outdoor temperature value input from the outdoor temperature sensor 520. Calculate the saturation pressure to allow the refrigerant to saturate. In addition, the low pressure sensor 530 receives a pressure value inside the low pressure gas pipe 430.

Subsequently, the controller 500 determines whether the saturation pressure is smaller than the refrigerant stagnation pressure (818). Here, the refrigerant stagnation pressure means a pressure in which a reliability value is added to the low pressure sensed by the low pressure sensor 270.

At this time, if the saturation pressure is not less than the refrigerant stagnation pressure, the controller 500 controls the shutoff valve 270 to be closed and controls the driving of the outdoor blower fan 290 to be stopped (819). Subsequently, the control unit 500 receives a heating chamber exit temperature value from the heating chamber exit side temperature sensor 301 installed at the exit side of the heating chamber 300 performing the heating operation (820), and the heating chamber 300 The average temperature of the outlet side of NELTA) is calculated (821).

Next, the controller 500 determines whether the average temperature of the outlet side of the heating chamber 300 is smaller than the optimum temperature (822).

At this time, the control unit 500 controls the heating capacity of the heating chamber 300 to perform the heating operation by controlling the flow rate control valve 260 to be tightened if the average temperature of the outlet side of the heating chamber 300 is not less than the heating capacity optimization temperature. This is ensured (825), if the average temperature of the outlet side of the heating chamber 300 is less than the heating capacity optimization temperature, the flow rate control valve 260 is controlled to be released to perform the cooling operation of the cooling chamber 300 to perform the cooling operation This is ensured (824). The controller 500 determines whether the heating capacity ratio is changed (830). At this time, if the heating capacity ratio is not changed to perform the heating subject operation, and if the heating capacity ratio is changed to determine whether the heating subject operation termination condition (816) and subsequent steps.

On the other hand, in step 818 of determining whether the saturation pressure is less than the refrigerant stagnation pressure, if the saturation pressure is less than the refrigerant stagnation pressure, the control unit 500 opens the flow control valve 260 and the shutoff valve 270, the outdoor Opening the electric expansion valve 280 to the set opening degree to stop the driving of the outdoor blowing fan 290 (827). Accordingly, the saturation pressure inside the outdoor heat exchanger 220 is increased.

Subsequently, the control unit 500 receives the low pressure value from the low pressure gas sensor 270 again (826).

Next, the control unit 500 determines whether the low pressure is greater than the cooling capacity optimization pressure (827).

At this time, if the low pressure is greater than the cooling capacity optimization pressure in order to secure the cooling capacity and improve the performance, the control unit 500 is controlled to reduce the opening of the outdoor electric expansion valve 280 to reduce the pressure of the low pressure pipe 430 (828). Accordingly, the cooling capacity and performance of the cooling chamber 300 is improved. On the other hand, if the low pressure is greater than the cooling capacity optimization pressure, the control unit 500 increases the opening degree of the outdoor electric expansion valve 280 to improve the cooling capacity and performance of the cooling chamber (300). The controller 500 determines whether the heating capacity ratio is changed (830). At this time, if the heating capacity ratio is not changed to perform the heating subject operation, and if the heating capacity ratio is changed to determine whether the heating subject operation termination condition (816) and subsequent steps.

In addition, in the structure of the present invention, when there is no receiver tank 202, the closing role of the shutoff valve 270 can be controlled by a full close of the outdoor electric expansion valve 280, thereby enabling the receiver tank ( It is also possible to configure and control the removal of the 202 and the shutoff valve 270.

By the simultaneous air-conditioning type multi-air conditioner and control method thereof according to the present invention as described above, the excessive operation of the compressor is prevented and consumed by preventing excessive bypass of the high-pressure gas refrigerant into the liquid pipe during the heating main body operation. There is an effect of saving power.

If the temperature of the outdoor unit where the outdoor unit is installed is lower than the heating capacity ratio, the outdoor heat exchanger is not used as an evaporator and the saturation pressure of the outdoor heat exchanger is prevented from being lower than the pressure inside the low pressure gas pipe. The phenomenon that the refrigerant is liquefied is prevented, and the internal pressure of the outdoor heat exchanger is prevented from being excessively low, thereby preventing freezing from occurring in the indoor heat exchanger.

Claims (11)

A high pressure gas pipe, a low pressure gas pipe, and a liquid pipe connected between the at least one outdoor unit and the plurality of air conditioning conversion sets; A flow control valve installed in the bypass pipe connecting the high pressure gas pipe and the liquid pipe; Comprising a control unit for calculating the average opening degree of the indoor electric expansion valve of the cooling room, if the heating capacity ratio is not less than the reference ratio during operation of the heating main body, and reducing the opening degree of the flow control valve if the calculated average opening is not greater than the reference opening Simultaneous air conditioning multi air conditioner. The method of claim 1, Further comprising an outdoor expansion valve and an outdoor blowing fan, The control unit performs superheat control using the outdoor expansion valve and low pressure control using the outdoor blower fan, and simultaneously controls the opening degree of the flow control valve according to the average opening degree of the cooling chamber. Air conditioner. An outdoor temperature sensor for detecting an outdoor temperature; Low pressure sensor for detecting the pressure inside the low pressure gas pipe; The saturation pressure of the outdoor heat exchanger is calculated at the outdoor temperature detected by the outdoor temperature sensor, and the refrigerant stagnation pressure is calculated using the pressure sensed by the low pressure sensor, and the cooling and heating capacity is compared by comparing the saturation pressure with the refrigerant stagnation pressure. A simultaneous air-conditioning type multi air conditioner including a control unit for improving operation or preventing refrigerant from stalling. The method of claim 3, wherein Installed in the bypass pipe connecting the high pressure gas pipe and the liquid pipe further includes a flow control valve for controlling the flow rate and a shutoff valve for blocking the refrigerant moving to the outdoor heat exchanger side and an outdoor blower fan, And the control unit blocks the flow rate control valve and the shut-off valve and stops the outdoor blower fan when performing the heating and cooling capability improving operation. The method of claim 3, wherein Installed in the bypass pipe connecting the high pressure gas pipe and the liquid pipe further includes a flow control valve for controlling the flow rate and a shutoff valve for blocking the refrigerant moving to the outdoor heat exchanger side and an outdoor blower fan, The control unit opens the flow control valve and the shutoff valve when stopping the refrigerant stagnation operation, stops the outdoor blower fan, and detects low pressure again so that the detected low pressure is not greater than the cooling capacity optimization pressure. And an increase in the opening degree of the expansion valve, and a decrease in the opening degree of the outdoor electric expansion valve when the sensed low pressure is greater than the cooling capacity optimization pressure. Determines whether the heating capacity ratio is higher than the standard ratio when operating the heating main If the heating capacity ratio is not less than the standard ratio control method of a simultaneous air-conditioning type multi air conditioner for adjusting the flow rate for the flow rate of the high pressure gas flowing into the liquid pipe from the high pressure gas pipe. The method of claim 6, The flow rate adjustment A method of controlling a simultaneous air-conditioning type multi air conditioner by controlling the opening degree of an outdoor electric expansion valve and performing a low pressure control and an open control of a shutoff valve by controlling the superheat degree and the air volume control of an outdoor blower fan. The method of claim 6, The flow rate adjustment Calculate the average opening of the electric motor expansion valve in the cooling room, And a flow rate is reduced if the calculated average opening is not greater than the reference opening, and the flow rate is increased if the calculated average opening is greater than the reference opening. It is determined whether the heating capacity ratio is higher than the standard ratio during the heating main operation. If the heating capacity ratio is less than the reference ratio, if the saturation pressure of the outdoor heat exchanger is less than the refrigerant stagnation pressure of the low pressure gas pipe to perform the refrigerant stagnation prevention operation, the saturation pressure of the outdoor heat exchanger is the refrigerant stagnation of the low pressure gas pipe Control method of a simultaneous air-conditioning type multi air conditioner to perform cooling and heating capacity securing operation if it is not less than pressure. The method of claim 9, The heating and cooling capacity securing operation Close the flow control valve and shutoff valve, stop the outdoor blower fan, If the average outlet temperature of the heating chamber is less than the optimum temperature, the opening degree of the flow regulating valve is increased. If the average outlet temperature of the heating chamber is not less than the optimum temperature, the opening degree of the flow regulating valve is increased. Reduced simultaneous air conditioning multi air conditioner. The method of claim 9, The refrigerant stagnation prevention operation Close the flow control valve and shutoff valve, stop the outdoor blower fan, When the low pressure of the low-pressure gas pipe is greater than the cooling capacity optimum pressure, the opening degree of the outdoor electric motor expansion valve is reduced, and if the low pressure of the low-pressure gas pipe is not greater than the cooling capacity optimum pressure, simultaneous air-conditioning and multi-air conditioning group.

Images