KR102550617B1 - Air conditioner and controlling method of thereof - Google Patents

Abstract

An air conditioner according to an embodiment of the present invention includes a supercooling electronic expansion valve for adjusting the flow rate of a refrigerant flowing to a compressor; a compressor for sucking in, compressing, and discharging the refrigerant; a temperature sensor measuring a discharge temperature of the refrigerant discharged from the compressor; and when the discharge temperature exceeds the reference temperature, adjusting the opening of the supercooled electronic expansion valve to increase the flow rate of the refrigerant flowing into the compressor, and monitoring whether the discharge temperature is below the reference temperature for a predetermined time. It includes a control unit that

Description

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

The present invention relates to an air conditioner and a control method thereof, and more particularly, to an air conditioner capable of effectively preventing an excessive rise in discharge temperature of a compressor and a control method thereof.

A multi-type air conditioner configures a refrigeration cycle by connecting a plurality of indoor units to one outdoor unit so as to perform a heating operation or a cooling operation targeting a plurality of indoor spaces. Such a multi-type air conditioner changes the capacity of the compressor according to the load of the indoor space, that is, the required capacity of the indoor unit.

During the heating or cooling operation of the multi-type air conditioner, the compressor performs a function of sucking in and compressing the low-pressure refrigerant and discharging it in a high-temperature and high-pressure state. When the discharge temperature of the compressor exceeds the normal range, the multi-type air conditioner is loaded or malfunctions. Therefore, the multi-type air conditioner controls the electronic expansion valve of the supercooling device to lower the discharge temperature of the compressor when the discharge temperature of the compressor excessively rises, and stops the system when the discharge temperature exceeds the threshold value.

As described above, the multi-type air conditioner can control the discharge temperature of the compressor by adjusting the flow rate of the refrigerant by adjusting the opening of the electronic expansion valve of the supercooling device. Currently, the discharge temperature of the compressor is controlled in an on-off manner. Specifically, when the discharge temperature is higher than the reference value, the discharge temperature control is turned on, and when the discharge temperature is lower than the reference value, the discharge temperature control is turned off. That is, when the discharge temperature is lowered below the reference value, the normal opening of the electronic expansion valve of the supercooling device immediately returns. For this reason, when the discharge temperature of the compressor is controlled by the conventional on-off method, when the reference value is reached, the control is repeatedly turned on and off, so that a constant cycle of hunting occurs.

The present invention, when controlling the electronic expansion valve of the supercooling device to prevent excessive rise in the discharge temperature of the compressor, adjusts the opening degree of the electronic expansion valve of the supercooling device by reflecting the cycle change of the compressor temperature, thereby providing a cycle of the discharge temperature of the compressor below the limit temperature. It is an object of the present invention to provide an air conditioner and a control method for stabilizing the air conditioner.

In addition, the present invention sets the temperature condition for ending the opening degree lower than the temperature condition for starting the opening degree control of the supercooled electronic expansion valve to prevent excessive rise in the discharge temperature of the compressor, thereby controlling the supercooled electronic expansion valve. An object of the present invention is to provide an air conditioner capable of securing a limited margin for the discharge temperature of a compressor and a control method thereof.

An air conditioner according to an embodiment of the present invention includes a compressor that sucks, compresses, and discharges a refrigerant; a supercooling electronic expansion valve controlling a flow rate of the refrigerant flowing to the compressor; a temperature measuring unit measuring a discharge temperature of the refrigerant discharged from the compressor; and a control unit controlling an operation of the supercooled electronic expansion valve to control the discharge temperature, wherein the control unit starts adjusting the opening degree of the supercooled electronic expansion valve when the discharge temperature exceeds a first reference temperature. And, when the discharge temperature is lowered to a second reference temperature lower than the first reference temperature, the opening degree control of the supercooled electronic expansion valve is terminated, and the discharge temperature is maintained for a predetermined time when the opening degree of the supercooled electronic expansion valve is adjusted. A buffer period for monitoring is set, and after the buffer period has elapsed, start and end of adjusting the opening degree of the supercooling electronic expansion valve are determined.

A control method of an air conditioner according to another embodiment of the present invention includes adjusting a flow rate of refrigerant flowing to a compressor by a supercooling electronic expansion valve; suctioning, compressing and discharging the refrigerant; measuring a discharge temperature of the refrigerant discharged from the compressor; setting a buffer period for monitoring a change in the discharge temperature for a predetermined time when the discharge temperature exceeds a first reference temperature; starting to adjust the opening degree of the supercooling electronic expansion valve after the buffer period has elapsed; and terminating the adjustment of the opening degree of the supercooling electronic expansion valve when the discharge temperature is lower than a second reference temperature after the buffer period has elapsed.

According to at least one of the embodiments of the present invention, the air conditioner can be operated with a stable cycle reflecting the effect of the change in the opening degree of the electronic expansion valve by adjusting the opening degree of the electronic expansion valve of the supercooling device by setting a predetermined buffer period.

In addition, according to at least one of the embodiments of the present invention, by setting the temperature condition for ending the opening adjustment lower than the temperature condition for starting the opening adjustment of the supercooled electronic expansion valve, a compressor for controlling the supercooled electronic expansion valve It is possible to efficiently secure a limiting margin for the discharge temperature of .

1A is a diagram showing the configuration of an air conditioner according to an embodiment of the present invention.
Figure 1b is a diagram showing the configuration of an air conditioner according to another embodiment of the present invention.
2 is a view for explaining a general method of controlling an electronic expansion valve of a supercooling device to control a discharge temperature of a compressor.
3 is a block diagram showing the configuration of an air conditioner according to an embodiment of the present invention.
4 is a diagram illustrating a control process of a supercooling electronic expansion valve according to an embodiment of the present invention.
5 is a diagram illustrating a control process of a supercooling electronic expansion valve according to another embodiment of the present invention.

Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings, but the same or similar elements are given the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used together in consideration of ease of writing the specification, and do not have meanings or roles that are distinct from each other by themselves. In addition, in describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiment disclosed in this specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in this specification, the technical idea disclosed in this specification is not limited by the accompanying drawings, and all changes included in the spirit and technical scope of the present invention , it should be understood to include equivalents or substitutes.

Terms including ordinal numbers, such as first and second, may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, terms such as "comprise" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

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

The air conditioner 100 according to an embodiment of the present invention may be a simultaneous cooling/heating type multi-air conditioner. In the multi air conditioner for simultaneous cooling and heating, a plurality of indoor units (B1, B2, B3, B4) are connected to one outdoor unit (A), and each indoor unit (B1, B2, B3, B4) is installed in each air conditioning space. can be made into a shape. In this case, each of the indoor units B1, B2, B3, and B4 is operated in one of heating and cooling operation modes to air-condition the room.

As shown in FIG. 1A, the simultaneous heating/cooling type multi-air conditioner 100 includes an outdoor unit (A), first, second, third and fourth indoor units (B1, B2, B3, B4) and a distributor (C). can include

The outdoor unit A may include first and second compressors 53 and 54, an outdoor heat exchanger 51, an outdoor heat exchanger fan 61, and a switching unit. Here, the switching unit may include a four-way valve 62. The suction parts of the first and second compressors 53 and 54 are connected by a common accumulator 52 . The first compressor 53 is an inverter compressor capable of varying the compression capacity of the refrigerant, and the second compressor 54 is a constant speed compressor having a constant compression capacity of the refrigerant.

The first and second discharge pipes 55 and 56 are connected to the discharge parts of the first and second compressors 53 and 54 . The first and second discharge pipes 55 and 56 are joined by a joining unit 57 . First and second oil separators 58 and 59 are installed in the first and second discharge pipes 55 and 56 to recover oil from the refrigerant discharged from the first and second compressors 53 and 54, respectively. . In the first and second oil separators 58 and 59, the first and second oil separators 58 and 59 guide the oil separated from the first and second oil separators 58 and 59 to the suction parts of the first and second compressors 53 and 54. , the second oil return pipes 30 and 31 are connected.

A high-pressure gas pipe 63 is connected to the bonding portion 57 to bypass the refrigerant discharged from the first and second compressors 53 and 54 without passing through the four-way valve 62 . In addition, the bonding portion 57 is connected to the four-way valve 62 and the third discharge pipe 68.

The outdoor heat exchanger (51) is connected to the four-way valve (62) through the first connection pipe (71). In the outdoor heat exchanger 51, the refrigerant is condensed or evaporated by heat exchange with outside air. In the simultaneous cooling and heating type multi-air conditioner 100, the outdoor heat exchanger 51 is used as a condenser during operation of all rooms for cooling or simultaneous operation of the main body of cooling, and the outdoor heat exchanger 51 is used as an evaporator during operation of all rooms for heating or simultaneous operation of the main body of heating. is used as Meanwhile, in order to facilitate heat exchange, the outdoor unit fan 61 is installed around the outdoor heat exchanger 51 to introduce air into the outdoor heat exchanger 51 .

On the liquid pipe 72 connecting the outdoor heat exchanger 51 and the distributor C, an outdoor electronic expansion valve 65 and a supercooling device 66 are installed.

The outdoor electronic vent valve 65 expands the refrigerant when operating the entire heating room or operating the heating main body simultaneously. Specifically, the outdoor electronic expansion valve 65 removes the refrigerant condensed in the first, second, third, and fourth indoor heat exchangers 11, 21, 31, and 41 during operation of the entire heating room or simultaneous operation of the heating main body. It expands before entering the outdoor heat exchanger (51).

The supercooling device 66 cools the refrigerant moving to the distributor C during operation of the cooling front chamber or simultaneous operation of the main body of cooling. The supercooler 66 includes a supercooler 66a installed around a part of the liquid pipe 72 and a part of the refrigerant moving to the distributor C disposed between the supercooler 66a and the distributor C. The bypass pipe 66b bypassing the inside of the supercooler 66a, the electronic expansion valve 66c installed in the bypass pipe 66b, and the number of connections between the supercooler 66a and the suction pipe 64 A pipe 66d may be included.

The distributor (C) is disposed between the outdoor unit (A) and the first, second, third, and fourth indoor units (B1, B2, B3, B4), so that all rooms are cooled, all rooms are heated, the cooling subject operates simultaneously, and the heating subject operates simultaneously. The refrigerant is distributed to the first, second, third and fourth indoor units B1, B2, B3 and B4 according to operating conditions. To this end, the distributor C may include a high-pressure gas header 81, a low-pressure gas header 82, a liquid header 83, and control valves (not shown).

The first, second, third, and fourth indoor units B1, B2, B3, and B4 include the first, second, third, and fourth indoor heat exchangers 11, 21, 31, and 41, the first and second indoor heat exchangers, respectively. The second, third, and fourth indoor electronic expansion valves 12, 22, 32, and 42 and the first, second, third, and fourth indoor unit fans 15, 25, 35, and 45 are included. The first, second, third, and fourth indoor electronic expansion valves 12, 22, 32, and 42 are connected to the first, second, third, and fourth indoor heat exchangers 11, 21, 31, and 41 at high pressure. It is installed on the first, second, third, and fourth indoor connection pipes 13, 23, 33, and 43 connecting the gas header 81.

The high-pressure gas header 81 is connected to one side of the high-pressure gas pipe 63 and the first, second, third, and fourth indoor heat exchangers 11, 21, 31, and 41 of the bonding portion 57, respectively. . In addition, the low-pressure gas header 82 is connected to the suction pipe 64 through the low-pressure gas pipe 75, and the other elements of the first, second, third, and fourth indoor heat exchangers 11, 21, 31, and 41 connected to the side The liquid header 83 is connected to one side of the supercooling device 66 and the first, second, third, and fourth indoor heat exchangers 11, 21, 31, and 41, respectively. The high-pressure gas header 81, the low-pressure gas header 82, and the liquid header 83 include a high-pressure gas pipe 63', a low-pressure gas pipe 75', and a liquid pipe 72' of another outdoor unit (not shown). Each may be further connected.

Figure 1b is a diagram showing the configuration of an air conditioner according to another embodiment of the present invention.

The air conditioner 100 according to another embodiment of the present invention may be a multi-cooling/heating switching type air conditioner. The cooling/heating switching type multi air conditioner may be configured such that a plurality of indoor units (B1, B2, B3, B4) and an outdoor unit (A) are connected by refrigerant pipes. In this case, the cooling/heating switching type multi-air conditioner may be switched to one of heating or cooling operation modes to air-condition the room. Such an air conditioner may be referred to as a heat pump type air conditioner.

As shown in FIG. 1B , the air conditioner 100 according to another embodiment of the present invention includes a plurality of indoor units B1, B2, B3, and B4 installed inside a building, and the indoor units B1 and B2. , B3, B4) may be configured to include an outdoor unit (A) connected. The indoor units B1, B2, B3, and B4 and the outdoor unit A may be connected through refrigerant pipes 10 and 20. The outdoor unit (A) is driven by the request of at least one of the indoor units (B1, B2, B3, and B4), and as the cooling/heating capacity required by the indoor units (B1, B2, B3, and B4) increases, the outdoor unit (A) The number of operating units and the number of operating compressors installed in the outdoor unit (A) may increase.

The indoor units (B1, B2, B3, B4) are installed around the indoor heat exchangers (11, 21, 31, 41) and the indoor heat exchangers (11, 21, 31, 41) that exchange heat between the refrigerant and the indoor air, indoor unit fans (15, 25, 35, 45) that circulate and indoor electronic expansion valves (12, 22, 32, 42) that expand the refrigerant flowing to the indoor heat exchanger (11, 21, 31, 41) during cooling. can be configured to include Here, the indoor heat exchangers 11, 21, 31, and 41 may function as evaporators during cooling operation and function as condensers during heating operation.

The outdoor unit (A) has an accumulator 52 that extracts only gaseous refrigerant from among the refrigerants supplied from the indoor units (B1, B2, B3, and B4), receives the gaseous refrigerant extracted from the accumulator 52, and compresses it into high-temperature and high-pressure gaseous refrigerant. The first and second compressors 53 and 54 that operate, the four-way valve 62 connected to the first and second compressors 53 and 54 and selecting the path of the compressed refrigerant according to the cooling operation or heating operation, the four-way valve 62 It is configured to include an outdoor heat exchanger 51 for exchanging heat between the refrigerant supplied from the valve 62 and outdoor air. Here, the first compressor 53 may be an inverter compressor capable of varying the compression capacity of the refrigerant, and the second compressor 54 may be a constant speed compressor having a constant compression capacity of the refrigerant. In addition, the outdoor heat exchanger 51 may function as a condenser during cooling operation and as an evaporator during heating operation. Meanwhile, around the outdoor heat exchanger 51 , an outdoor fan 61 may be provided to introduce outdoor air into the outdoor heat exchanger 51 .

First and second oil separators 58 and 59 are installed in pipes connecting the first and second compressors 53 and 54 and the four-way valve 62. The first and second oil separators 58 and 59 are connected to the suction side of the first and second compressors 53 and 54. In this case, the first and second oil separators 58 and 59 separate oil from the refrigerant discharged from the first and second compressors 53 and 54, and the separated oil is separated from the first and second compressors 53 and 54. 54), an appropriate amount of oil is maintained in the first and second compressors 53 and 54. The first and second oil separators 58 and 59 and the suction side pipes of the first and second compressors 53 and 54 are connected through first and second oil return pipes 30 and 31, Oil is moved through the first and second oil return pipes 30 and 31 .

The refrigerant pipe 10 guides the refrigerant discharged from the outdoor heat exchanger 51 to the indoor heat exchangers 11, 21, 31, and 41. The refrigerant pipe 10 includes an outdoor electronic expansion valve (EEV, 65) that expands the condensed refrigerant during heating operation, and a supercooling device that supercools the refrigerant moving to the indoor heat exchanger (11, 21, 31, 41) during cooling operation. (66) is installed.

The outdoor electronic expansion valve 65 is fully open during cooling operation, and passes the refrigerant condensed in the outdoor heat exchanger 51 without expanding it. On the other hand, during heating operation, the refrigerant is opened to a predetermined size, and the refrigerant condensed in the indoor heat exchanger (11, 21, 31, 41) is expanded into a sprayed liquid before flowing into the outdoor heat exchanger (51).

The supercooling device 66 includes a subcooler 66a installed surrounding some of the refrigerant pipes 10 and a refrigerant pipe connected to the indoor heat exchangers 11, 21, 31, 41 through the supercooler 66a ( 10) to bypass some of the refrigerant moving through the refrigerant pipe 10 into the supercooler 66a, a bypass pipe 66b, and an electronic expansion valve 66c installed in the bypass pipe 66b , the return pipe 66d connecting the supercooler 66a and the input side refrigerant pipe 64 of the accumulator 52, the return pipe 66d and the discharge side pipe of the first and second compressors 53 and 54 ( 62") is installed at the connection between the overheating pipe 88, the recovery pipe 66d and the overheating pipe 88, and depending on the temperature of the refrigerant discharged from the supercooler 66a, the recovery pipe 66d or overheating It may be configured to include a valve 89 for converting the flow direction of the refrigerant into the pipe 88.

Here, a space is formed inside the subcooler 66a, and the refrigerant pipe 10 is installed through the subcooler 66a. When the air conditioner 100 is driven in a cooling cycle, the refrigerant moving along the refrigerant pipe 10 exchanges heat with the refrigerant filled in the supercooler 66a to lower its temperature. To this end, the electronic expansion valve 66c expands the refrigerant moving to the supercooler 66a through the bypass pipe 66b and converts it into a low-temperature, low-pressure liquid refrigerant in a spray state, and the expanded refrigerant is transferred to the supercooler 66a. ) Is filled in the inside and heat exchanges with the refrigerant moving along the refrigerant pipe (10).

On the other hand, in order to detect the temperature of the refrigerant introduced/discharged from the supercooler 66, the refrigerant pipe 10 on the discharge side of the supercooler 30 and the discharge side of the electronic expansion valve 66c in the bypass pipe 66b Temperature sensors (101, 102, 103) are installed respectively.

In addition, temperature sensors 104 and 105 for detecting the temperature of the refrigerant discharged from the first and second compressors 53 and 54 are provided in the refrigerant pipes on the discharge side of the first and second compressors 53 and 54. A temperature sensor 106 for detecting the temperature of the refrigerant flowing into the accumulator 52 is also installed in the refrigerant pipe on the input side of the accumulator 52.

The valve 89 selects a flow direction of the refrigerant discharged from the inside of the supercooler 66a according to the temperature of the refrigerant measured by the temperature sensor 103 . Specifically, when the temperature of the refrigerant discharged from the inside of the supercooler 66a is maintained within a normal temperature range, the valve 89 opens a passage through which the refrigerant is connected to the recovery pipe 66d and connects to the superheated pipe 88. block the euro. On the other hand, when the temperature of the refrigerant discharged from the inside of the supercooler 66a is higher than the normal temperature range, the valve 89 is connected to the recovery pipe 66d to prevent damage to the first and second compressors 53 and 54. The connected flow path is blocked, and the flow path connected to the overheating pipe 88 is opened. In this case, a check valve 85 is installed in the overheating pipe 88 to prevent the refrigerant discharged from the first and second compressors 53 and 54 from flowing backward to the supercooler 66a.

On the other hand, a dryer 110 for removing moisture inside the refrigerant pipe 10 is installed in the refrigerant pipe 10, and the refrigerant passing through the dryer 110 is bypassed in the refrigerant pipe 10 and It flows toward the heat exchanger (11, 21, 31, 41).

Hereinafter, in the air conditioner shown in FIGS. 1A and 1B , in order to prevent the discharge temperature of the compressor from excessively rising, embodiments of controlling the electronic expansion valve of the supercooling device will be described in detail.

2 is a view for explaining a general method of controlling an electronic expansion valve of a supercooling device to control a discharge temperature of a compressor.

In order to prevent an excessive rise in the discharge temperature of the compressor, the air conditioner may control the electronic expansion valve of the supercooling device. Specifically, when the discharge temperature of the compressor excessively rises, the discharge temperature of the compressor may be controlled to be lowered by controlling the opening of the electronic expansion valve of the supercooling device to flow the refrigerant into the accumulator. Hereinafter, in the present invention, the electronic expansion valve of the supercooling device is also referred to as a supercooling electronic expansion valve or a supercooling EEV (Electronic Expansion Valve).

Control of the supercooled electronic expansion valve may start when an entry condition is satisfied and may end when an end condition is satisfied. Here, the entry condition may be whether a discharge temperature of the compressor exceeds a reference value during cooling control. The termination condition may be whether or not the discharge temperature of the compressor is lowered to a reference value or less after control of the supercooling electronic expansion valve is started.

Meanwhile, when controlling the supercooling electronic expansion valve, the air conditioner may adjust the opening degree of the supercooling electronic expansion valve. Specifically, the air conditioner may change the refrigerant flow rate by controlling the pulse value for opening the supercooling electronic expansion valve.

In this way, by adjusting the opening degree of the supercooling electronic expansion valve during the cooling operation, it is possible to prevent the discharge temperature of the compressor from excessively rising. However, in the past, when the discharge temperature of the compressor exceeds the reference value, the control of the opening degree of the supercooled electronic expansion valve starts, and when the discharge temperature falls below the reference value, the control of the opening degree of the supercooled electronic expansion valve ends. was performed. In this case, the cycle for the discharge temperature of the compressor is not stabilized due to the absence of the buffer section, and a phenomenon in which the cycle is continuously and repeatedly hunted occurs.

In FIG. 2, (a) is a graph showing the correspondence between the discharge temperature of the compressor and the opening degree of the supercooled electronic expansion valve, and (b) is a graph showing the correspondence between the low pressure and the temperature of the liquid pipe.

Referring to (a) shown at the top, when the discharge temperature of the compressor exceeds 95 degrees, the opening degree of the supercooling electronic expansion valve is adjusted. In this case, when the discharge temperature of the compressor exceeds 95 degrees, the opening degree of the supercooled electronic expansion valve starts to be adjusted, and when the discharge temperature of the compressor falls below 95 degrees, the opening degree control is finished and the supercooled electronic expansion valve is normally operated. . Thereafter, when the discharge temperature of the compressor again exceeds 95 degrees, the air conditioner adjusts the opening degree of the supercooling electronic expansion valve again until the discharge temperature of the compressor is 95 degrees or less. This process is performed repeatedly. In this case, as shown in 210 of (a), the cycle for the discharge temperature of the compressor is not stabilized, and a phenomenon in which the cycle continuously and repeatedly hunts occurs.

Referring to (b) shown at the bottom, when the discharge temperature of the compressor increases, the low pressure and liquid pipe temperature decrease. Specifically, when the discharge temperature of the compressor increases, the current low pressure (ie, evaporation pressure) decreases. In addition, when the discharge temperature of the compressor increases, the opening of the supercooled electronic expansion valve is adjusted so that more supercooled refrigerant flows and the temperature of the liquid pipe decreases. Referring to 220 of (b), the current low pressure and liquid pipe temperatures are lowered.

That is, according to the conventional on-off method of controlling the opening of the supercooled electronic expansion valve, as shown in FIG. 2 (a), the cycle for the discharge temperature of the compressor is not stabilized and continuously and repeatedly hunts. Accordingly, an increase in the discharge temperature of the compressor can be prevented due to the one-step control based on the limit temperature, but there is a problem in that the discharge temperature cycle is not stabilized.

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

The air conditioner 100 according to an embodiment of the present invention may be a simultaneous cooling/heating type multi air conditioner shown in FIG. 1A or a cooling/heating switching type multi air conditioner shown in FIG. 1B. The air conditioner 100 according to an embodiment of the present invention may include a compressor 310, a temperature measuring unit 320, a supercooling EEV 330, and a controller 340.

The compressor 310 may suction and compress the low-pressure refrigerant and discharge it in a high-temperature and high-pressure state.

The temperature measurement unit 320 may detect the temperature and temperature change of the components of the air conditioner 100, the refrigerant flowing through the refrigerant pipe, and the outside air of the air conditioner 100. To this end, the temperature measuring unit 320 may detect the temperature of a fluid or object surface using a detection element, convert the detected temperature into an electrical signal, and transmit or output the detected temperature. Here, the detection element may include a thermistor, platinum, nickel, or a thermocouple.

According to an embodiment, the temperature measuring unit 320 may measure the discharge temperature and suction temperature of the compressor 310 . In this case, the temperature measuring unit 320 may be respectively disposed at a portion where the refrigerant is sucked into the compressor 310 and at a portion where the refrigerant is discharged from the compressor 310 . The temperature measurement unit 320 may output the measured discharge temperature and suction temperature of the compressor 310 to the control unit 340 .

The supercooling EEV 330 adjusts the amount of refrigerant flowing by adjusting the opening degree.

Specifically, the opening degree of the supercooling electronic expansion valve 330 may be adjusted by changing a pulse value for the opening degree of the supercooling electronic expansion valve 330 . The flow rate of the refrigerant flowing through the supercooled electronic expansion valve 330 is determined by the pulse value for opening the supercooled electronic expansion valve 330, and the discharge temperature of the compressor 310 can be controlled accordingly.

As the flow rate of the refrigerant increases, suction and discharge pressures of the compressor 310 may increase. Specifically, as the amount of refrigerant increases, the amount to be condensed increases, and accordingly, the condensation pressure increases. When the condensation pressure increases, the evaporation pressure also increases, which leads to an increase in the suction and discharge pressures of the compressor 310 .

The controller 340 may control components constituting the air conditioner 100 when the air conditioner 100 performs a cooling operation or a heating operation.

The controller 340 may control the discharge temperature of the compressor 310 . When the discharge temperature of the compressor 310 exceeds the normal range, a load may be applied to the air conditioner 100 or a malfunction may occur. Accordingly, the control unit 340 may control the discharge temperature of the compressor 310 within a predetermined range. In addition, the control unit 340 controls the supercooling electronic expansion valve 330 to lower the discharge temperature when the discharge temperature of the compressor 310 rises excessively, and the air conditioner 100 when the discharge temperature exceeds the threshold value. can shut down the system.

When the discharge temperature is controlled within a predetermined range, the controller 340 may set the opening degree of the supercooling electronic expansion valve 330 installed in the refrigerant pipe. Specifically, the controller 340 calculates the cooling load or heating load based on the difference between the required capacity of the indoor unit and the current temperature and the set temperature, and calculates the opening degree of the supercooling electronic expansion valve 330 in response to the cooling load or heating load. can be set. Specifically, the controller 340 may set a pulse value for opening the supercooling electronic expansion valve 330 .

In order to lower the discharge temperature, the control unit 340 may adjust the opening degree of the supercooling electronic expansion valve 330 . Specifically, the control unit 340 may change the pulse value for opening the supercooling electronic expansion valve 330 . The flow rate of the refrigerant may be determined corresponding to the opening degree of the supercooled electronic expansion valve 330, and accordingly, the discharge temperature of the compressor 310 may vary.

According to an embodiment, the control unit 340 enters a process of adjusting the opening degree of the supercooling electronic expansion valve 330 when the discharge temperature of the compressor 310 rises beyond the reference temperature, and the discharge temperature of the compressor 310 is When the temperature is lowered below the reference temperature, the process of adjusting the opening degree may be terminated. This will be described later in the description of FIG. 4 .

According to another embodiment, when the discharge temperature of the compressor 310 rises beyond the first reference temperature, the control unit 340 enters a process of adjusting the opening degree of the supercooling electronic expansion valve 330, and the discharge temperature of the compressor 310 When the temperature is lowered to the second reference temperature or less, the process of adjusting the opening degree may be terminated. Here, the second reference temperature may be set lower than the first reference temperature. This will be described later in the description of FIG. 5 .

When adjusting the opening degree of the supercooling electronic expansion valve 330, the controller 340 may set a buffer section for adjusting the opening degree. Here, the buffer section may be a section for monitoring the discharge temperature of the compressor 310 after adjusting the opening degree of the supercooling electronic expansion valve 330 in order to stabilize the discharge temperature cycle of the compressor 310 . According to one embodiment, the buffer period may be set to 30 seconds. In this case, the control unit 340 may determine whether the discharge temperature is lowered below the reference temperature during the set buffer period, and may adjust the opening degree of the supercooling electronic expansion valve 330 again if the temperature exceeds the reference temperature.

Depending on the embodiment, the controller 340 may be formed inside or outside the outdoor unit and at least one indoor unit.

4 is a diagram illustrating a control process of a supercooling electronic expansion valve according to an embodiment of the present invention.

According to the control process of the supercooled electronic expansion valve according to an embodiment of the present invention, in order to prevent an excessive increase in the discharge temperature of the compressor 310, the control unit 340 determines whether the discharge temperature of the compressor 310 exceeds the reference temperature. In this case, the opening degree of the supercooling electronic expansion valve can be adjusted.

In this case, the controller 340 may set a buffer section for adjusting the opening degree of the supercooling electronic expansion valve, and adjust the opening degree of the supercooling electronic expansion valve during the corresponding buffer section. Therefore, after adjusting the opening degree of the supercooling electronic expansion valve, the discharge temperature of the compressor 310 is monitored during the buffer period, and if the discharge temperature of the compressor 310 exceeds the reference temperature, the control unit 340 controls the supercooling electronic expansion valve again. opening can be adjusted.

When the discharge temperature of the compressor 310 is lowered to the reference temperature or less until the buffer period elapses, the control unit 340 may end the control process of the supercooled electronic expansion valve. That is, according to the present embodiment, the control process is entered when the discharge temperature of the compressor 310 is higher than the reference temperature, and the control process is ended when the discharge temperature of the compressor 310 is lowered to the reference temperature or less. .

The discharge temperature of the compressor 310 is detected (S401).

Specifically, temperature sensors positioned at both ends of the compressor 310 may detect the temperature of the refrigerant discharged from the compressor 310 and output the sensed temperature of the refrigerant to the control unit 340 . Accordingly, the controller 340 detects the discharge temperature of the compressor 310 .

It is determined whether the discharge temperature exceeds the reference temperature (S402).

If it is determined that the discharge temperature of the compressor 310 is below the reference temperature (S402-No), the controller 340 performs normal control (S406). Here, the normal control of the supercooled electronic expansion valve may be to drive the pulse value for the opening degree of the supercooled electronic expansion valve 330 to a preset value when the discharge temperature of the compressor 310 is within a normal range.

On the other hand, if the control unit 340 determines that the discharge temperature of the compressor 310 exceeds the reference temperature (S402-Yes), it may enter a process of controlling the opening of the supercooling electronic expansion valve. In this case, the control unit 340 sets a buffer section for adjusting the opening degree of the supercooling electronic expansion valve (S403).

Here, the buffer section for adjusting the opening degree of the supercooling electronic expansion valve is a section monitoring the discharge temperature of the compressor 310 after adjusting the opening degree of the supercooling electronic expansion valve 330 in order to stabilize the discharge temperature cycle of the compressor 310. can be According to one embodiment, the buffer period may be set to 30 seconds. However, the present invention is not limited thereto, and the buffer period may be set in various ways based on the operating conditions of the system, the installation environment, and surrounding conditions.

The control unit 340 adjusts the opening degree of the supercooling electronic expansion valve (S404).

Specifically, the controller 340 may adjust the pulse value for opening the supercooling electronic expansion valve. According to an embodiment, the control unit 340 may adjust the opening degree of the supercooling electronic expansion valve based on the following [Equation 1].

Pulse (pls) for supercooling electronic expansion valve opening degree = Current pulse (pls) for supercooling electronic expansion valve opening degree + 10 pulses (pls) [Equation 1]

That is, the controller 340 may increase the pulse value for the opening degree of the supercooling electronic expansion valve by 10 pulse values from the current pulse value for the opening degree of the supercooling electronic expansion valve. As the pulse value for opening increases, the amount of refrigerant flowing into the compressor 310 may increase.

The controller 340 determines whether the discharge temperature is equal to or less than the reference temperature (S405).

According to one embodiment, the reference temperature may be 95 degrees. However, the present invention is not limited thereto, and the reference temperature may be variously set based on the load or operating conditions of the system, installation environment, and the like.

In this case, if the discharge temperature of the compressor 310 exceeds the reference temperature (S405-No), the controller 340 returns to step S404 and adjusts the opening degree of the supercooling electronic expansion valve. In this case, the control unit 340 may adjust the opening degree of the supercooling electronic expansion valve based on [Equation 1] described above. The control unit 340 monitors whether the discharge temperature of the compressor 310 is equal to or less than the reference temperature during the buffer section after adjusting the opening degree of the supercooling electronic expansion valve.

Meanwhile, if it is determined that the discharge temperature of the compressor 310 is equal to or less than the reference temperature in step S405 (S405-Yes), the control unit 340 ends the process of controlling the opening of the supercooled electronic expansion valve. In this case, the control unit 340 performs normal control of the supercooling electronic expansion valve (S406).

According to this embodiment, the opening degree of the supercooling electronic expansion valve can be adjusted periodically in the buffer section. That is, when the discharge temperature of the compressor 310 rises beyond the reference temperature, after changing the opening degree of the supercooling electronic expansion valve, it is determined whether the discharge temperature cycle of the compressor 310 is stabilized during the buffer section, and the discharge temperature becomes the reference temperature. When the temperature is below the reference temperature, normal control of the supercooled electronic expansion valve is performed, and when the discharge temperature does not fall below the reference temperature, the opening degree of the supercooled electronic expansion valve is adjusted again. As a result, the air conditioner 100 can be operated with a stable discharge temperature cycle of the compressor 310 reflecting the influence of the change in the opening degree of the supercooled electronic expansion valve.

5 is a diagram illustrating a control process of a supercooling electronic expansion valve according to another embodiment of the present invention.

According to the control process of the supercooled electronic expansion valve according to another embodiment of the present invention, in order to prevent an excessive increase in the discharge temperature of the compressor 310, the control unit 340 sets the discharge temperature of the compressor 310 to the first reference temperature. When it exceeds the temperature, the opening degree of the supercooling electronic expansion valve may start to be adjusted, and when the discharge temperature of the compressor 310 is lowered to the second reference temperature or less, the opening degree of the supercooling electronic expansion valve may end.

In this case, the controller 340 may set a buffer section for adjusting the opening degree of the supercooling electronic expansion valve, and adjust the opening degree of the supercooling electronic expansion valve during the corresponding buffer section. Therefore, after adjusting the opening degree of the supercooling electronic expansion valve, the discharge temperature of the compressor 310 is monitored during the buffer period, and if the discharge temperature of the compressor 310 exceeds the reference temperature, the control unit 340 controls the supercooling electronic expansion valve again. opening can be adjusted.

When the discharge temperature of the compressor 310 is lowered to the second reference temperature or less until the buffer period elapses, the control unit 340 may end the control process of the supercooled electronic expansion valve. That is, according to the present embodiment, when the discharge temperature of the compressor 310 is higher than the first reference temperature, the control process is entered, and when the discharge temperature of the compressor 310 is lowered to the second reference temperature or less, the control process can be terminated.

Here, the second reference temperature may be set lower than the first reference temperature. That is, the temperature of the control end condition may be set lower than the temperature of the control entry condition. Accordingly, a margin for limiting the discharge temperature of the compressor 310 may be secured.

The discharge temperature of the compressor 310 is detected (S501).

Specifically, temperature sensors positioned at both ends of the compressor 310 may detect the temperature of the refrigerant discharged from the compressor 310 and output the sensed temperature of the refrigerant to the control unit 340 . Accordingly, the controller 340 detects the discharge temperature of the compressor 310 .

It is determined whether the discharge temperature exceeds the first reference temperature (S502).

According to an embodiment, the first reference temperature may be 95 degrees. However, the present invention is not limited thereto, and the first reference temperature may be variously set based on the load or operating conditions of the system, installation environment, and the like.

If the discharge temperature of the compressor 310 is equal to or less than the first reference temperature (S502-No), the controller 340 performs normal control (S506). Here, the normal control of the supercooled electronic expansion valve may be to drive the pulse value for the opening degree of the supercooled electronic expansion valve 330 to a preset value when the discharge temperature of the compressor 310 is within a normal range.

On the other hand, if the controller 340 determines that the discharge temperature of the compressor 310 exceeds the first reference temperature (S502-Yes), it may enter a process of controlling the opening of the supercooling electronic expansion valve. In this case, the control unit 340 sets a buffer section for adjusting the opening degree of the supercooling electronic expansion valve (S503).

Here, the buffer section for adjusting the opening degree of the supercooling electronic expansion valve is a section monitoring the discharge temperature of the compressor 310 after adjusting the opening degree of the supercooling electronic expansion valve 330 in order to stabilize the discharge temperature cycle of the compressor 310. can be According to one embodiment, the buffer period may be set to 30 seconds. However, the present invention is not limited thereto, and the buffer period may be set in various ways based on the operating conditions of the system, the installation environment, and surrounding conditions.

The control unit 340 adjusts the opening degree of the supercooling electronic expansion valve (S504).

Specifically, the controller 340 may adjust the pulse value for opening the supercooling electronic expansion valve. According to an embodiment, the control unit 340 may increase the pulse value for the opening degree of the supercooling electronic expansion valve by 10 pulse values from the current pulse value for the opening degree of the supercooling electronic expansion valve. As the pulse value for opening increases, the amount of refrigerant flowing into the compressor 310 may increase.

The control unit 340 determines whether the discharge temperature is equal to or less than the second reference temperature (S505).

Here, the second reference temperature may be set to a lower value than the first reference temperature. According to an embodiment, the second reference temperature may be 90 degrees. However, the present invention is not limited thereto, and the second reference temperature may be variously set based on the load or operating conditions of the system, installation environment, and the like.

If the discharge temperature of the compressor 310 exceeds the second reference temperature (S505-No), the control unit 340 returns to step S504 and adjusts the opening degree of the supercooling electronic expansion valve. In this case, the control unit 340 may adjust the opening degree of the supercooling electronic expansion valve as described above in step S504. The control unit 340 monitors whether the discharge temperature of the compressor 310 is equal to or less than the second reference temperature during the buffer period after adjusting the opening degree of the supercooling electronic expansion valve.

Meanwhile, if it is determined in step S505 that the discharge temperature of the compressor 310 is equal to or less than the second reference temperature (S505-Yes), the controller 340 ends the process of controlling the opening degree of the supercooled electronic expansion valve. In this case, the control unit 340 performs normal control of the supercooling electronic expansion valve (S506).

According to this embodiment, when the discharge temperature of the compressor 310 exceeds the first reference temperature, the opening degree of the supercooling electronic expansion valve is started to be adjusted, and the discharge temperature of the compressor 310 is lowered to the second reference temperature or less. Adjustment of the opening degree of the supercooling electronic expansion valve may be terminated. Here, the second reference temperature is set lower than the first reference temperature. That is, by setting the temperature condition for ending the opening adjustment lower than the temperature condition for starting the opening adjustment of the supercooled electronic expansion valve, the limiting margin for the discharge temperature of the compressor 310 for controlling the supercooled electronic expansion valve can be secured

The above-described present invention can be implemented as computer readable code on a medium on which a program is recorded. The computer-readable medium includes all types of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable media include Hard Disk Drive (HDD), Solid State Disk (SSD), Silicon Disk Drive (SDD), ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc. , and also includes those implemented in the form of a carrier wave (eg, transmission over the Internet). Also, the computer may include the control unit 180 of the terminal. Accordingly, the above detailed description should not be construed as limiting in all respects and should be considered illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

100: air conditioner 310: compressor
320: temperature measuring unit 330: supercooling electronic expansion valve
340: control unit

Claims (9)

A compressor that sucks in, compresses, and discharges the refrigerant;
a supercooling electronic expansion valve controlling a flow rate of the refrigerant flowing to the compressor;
a temperature measuring unit measuring a discharge temperature of the refrigerant discharged from the compressor; and
A control unit controlling an operation of the supercooling electronic expansion valve to control the discharge temperature;
The control unit,
When the discharge temperature rises beyond a first reference temperature, the opening degree of the supercooling electronic expansion valve is started to be adjusted;
When the discharge temperature is lowered to a second reference temperature lower than the first reference temperature, the opening degree control of the supercooling electronic expansion valve is terminated,
An air conditioner that sets a buffer period for monitoring the discharge temperature for a predetermined time when adjusting the opening of the supercooled electronic expansion valve, and determines start and end of adjusting the opening of the supercooled electronic expansion valve after the buffer period has elapsed. According to claim 1,
The control unit,
The air conditioner that increases the opening degree of the supercooled electronic expansion valve by 10 pulses from the current pulse (pls) value of the opening degree of the supercooled electronic expansion valve when adjusting the opening degree of the supercooled electronic expansion valve. delete According to claim 1,
The control unit,
The air conditioner determines the opening degree of the supercooling electronic expansion valve periodically in the buffer section. According to claim 1,
When the discharge temperature of the refrigerant is equal to or less than the first reference temperature,
The control unit,
An air conditioner that performs normal control of driving a pulse value for opening of the supercooling electronic expansion valve to a preset value. According to claim 1,
The first reference temperature is set to 95 degrees,
The second reference temperature is set to 90 degrees air conditioner. delete According to claim 1,
The air conditioner in which the predetermined time of the buffer section is set to 30 seconds. adjusting the flow rate of the refrigerant flowing to the compressor by the supercooling electronic expansion valve;
suctioning, compressing and discharging the refrigerant;
measuring a discharge temperature of the refrigerant discharged from the compressor;
setting a buffer period for monitoring a change in the discharge temperature for a predetermined time when the discharge temperature exceeds a first reference temperature;
starting to adjust the opening degree of the supercooling electronic expansion valve after the buffer period has elapsed; and
When the discharge temperature is lower than the second reference temperature after the buffer period has elapsed, the control method of the air conditioner terminates the opening degree adjustment of the supercooling electronic expansion valve.

Images