KR100697450B1 - Liquid cooling material influx preventing method of an airconditioner - Google Patents

Abstract

The present invention relates to a liquid refrigerant inflow prevention control method of the air conditioner, the first step of determining whether the temperature of the compressor suction pipe is less than T1 ℃ during the cooling operation of the air conditioner, and the temperature of the compressor suction pipe If it is less than T1 ° C, the hot gas bypass valve 202 is turned on to supply hot gas discharged from the compressor to the accumulator 190, and if the temperature of the compressor suction pipe is not less than T1 ° C, And a second step of maintaining the hot gas bypass valve 202 in an off state. Therefore, the liquid refrigerant flowing into the suction pipe of the compressor can be vaporized using hot gas discharged from the compressor. Therefore, the liquid refrigerant flows into the compressor, causing the compressor to become overloaded and the parts burn out. You can prevent it.

Air Conditioner, Liquid Refrigerant, Compressor, Hot Gas Bypass Piping, Hot Gas, Accumulator

Description

Liquid cooling material influx preventing method of an airconditioner

1 is a configuration diagram of a refrigerant cycle of a general multi-type air conditioner.

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

3 is a block diagram showing the configuration of an air conditioner for preventing liquid refrigerant inflow.

4 is a flowchart illustrating a liquid refrigerant inflow prevention control method of an air conditioner according to the present invention.

* Explanation of symbols for main parts of drawings *

140: indoor unit 180: outdoor unit

182: inverter compressor 184: constant speed compressor

186: oil separator 187: solenoid valve

188: bypass pipe 189: oil conduit pipe

192: four sides 190: accumulator

194: outdoor heat exchanger 196: outdoor fan

200: hot gas bypass pipe 202: hot gas bypass valve

300: compressor suction piping temperature sensor 302: compressor discharge piping temperature sensor

The present invention relates to a control method of an air conditioner, and in particular, during the cooling operation, the temperature of the compressor suction stage is drastically lowered so that the liquid refrigerant inflow prevention control method of the air conditioner to prevent the liquid refrigerant from flowing into the compressor as it is. It is about.

An air conditioner is a device that is arranged in a room, living room, office, or business store to adjust the temperature, humidity, cleanliness, and airflow of the air to maintain a comfortable indoor environment. It is divided into (seperate type or split type).

The integrated type and the separated type are functionally the same, but the integrated type integrates the functions of cooling and heat dissipation to install a hole in the wall of the house or hang the device on the window, and the separate type installs an indoor unit that performs cooling / heating on the indoor side. In addition, the outdoor unit installed the outdoor unit that performs the heat dissipation and compression function, and then connected the two separate devices by the refrigerant pipe.

In general, one outdoor unit is installed in correspondence with one indoor unit. However, in the case of a building having several rooms, several outdoor units must be purchased to correspond to the indoor unit installed in each room. Since each outdoor unit must have a certain area of space, it is not efficient in terms of space usage.

Therefore, the development of a multi-type air conditioner capable of cooling and heating several rooms at once by connecting several indoor units to one outdoor unit is actively progressing.

1 is a configuration diagram of a refrigerant cycle of a general multi-type air conditioner.

The multi-type air conditioner includes an indoor unit (10) having a plurality of indoor heat exchangers (11a, 11b, 11c) arranged in the room and performing cooling / heating functions, and an outdoor unit (1) arranged outdoors. .

The outdoor unit (1) has an inverter compressor (2) and a constant speed compressor (4), which serve to compress the refrigerant, an outdoor heat exchanger (6), which serves to dissipate the compressed refrigerant, and the outdoor heat exchanger (6). And an outdoor fan 8 disposed at the rear of the pump to promote heat dissipation of the refrigerant.

An electronic expansion valve (LEV) 13a which allows the refrigerant to expand and depressurize before being introduced into the corresponding indoor heat exchangers 11a, 11b, and 11c in the downstream side of the outdoor heat exchanger 6 along the flow direction of the refrigerant during the cooling operation. , 13b and 13c are provided, respectively.

On the other hand, the inverter compressor (2) and the constant speed compressor (4) has a compression capacity corresponding to half (50%) of the maximum cooling / heating load of the indoor unit (1), respectively, the discharge end of each compressor is It is in contact with each other (see "A") before entering the outdoor heat exchanger (6).

Subsequently, the operation of the general multi-type air conditioner will be described (hereinafter, referred to as cooling operation).

The high temperature and high pressure gas refrigerant compressed by the compressors 2 and 4 is guided to the outdoor heat exchanger 6 by the action of a four-sided direction, and then condensed while being radiated in the process of passing through the outdoor heat exchanger 6. The liquid crystal is phase-converted to a high-temperature, high-pressure liquid refrigerant, and then converted to a low-temperature low-pressure state while passing through the electromagnetic expansion valves 13a, 13b, and 13c, and then flows into the indoor heat exchangers 11a, 11b, and 11c. At this time, the refrigerant introduced into the indoor heat exchanger is phase-converted to the gaseous refrigerant by the evaporation action, and then is led to the suction stages of the compressors 2 and 3 by the action of the four sides.

At this time, the temperature control of the air conditioning space (ie, indoor) is performed by heat exchange between the refrigerant passing through the indoor heat exchangers 11a, 11b, and 11c and the indoor air. That is, the refrigerant passing through the indoor heat exchanger takes heat away from the air passing through the indoor heat exchanger and evaporates, and the indoor air is re-introduced into the air conditioning space in a state where the temperature is lowered by this evaporation action, so that the temperature of the air conditioning space is As the heat exchange proceeds repeatedly, it becomes lower gradually.

Compared to a general air conditioner using only one indoor unit connected to one outdoor unit, the above-described multi-type air conditioner can cool / heat several rooms at the same time by using one outdoor unit. It is advantageous.

On the other hand, if the air conditioner continues to cool at a low temperature, the temperature of the refrigerant circulating in the cooling cycle gradually decreases in the order of the compressor → outdoor heat exchanger → electromagnetic expansion valve → indoor heat exchanger → compressor. A liquid refrigerant that is not yet vaporized (hereinafter, referred to as a 'liquid refrigerant') may be introduced into the suction pipe of the compressor. The amount of these liquid refrigerants increases gradually as the low temperature cooling operation continues.

In order to prevent the liquid refrigerant introduced into the suction pipe of the compressor from being sucked into the compressor as it is, an accumulator (not shown) for filtering the liquid refrigerant is generally installed in the suction pipe of the compressor. In the case where the liquid refrigerant is a small amount, the accumulation of the liquid refrigerant into the compressor does not occur when the accumulator filters them out. However, in a case where the supercooling state in which the amount of the liquid refrigerant exceeds the accumulator capacity continues, there is a method to prevent the liquid refrigerant that overflowed beyond the accumulator capacity from being sucked into the compressor. none.

When the liquid refrigerant flows into the compressor, the compressor is overloaded and the parts are burned out. Therefore, in order to prevent the liquid refrigerant from flowing into the compressor during the cooling operation, other means other than the accumulators generally used are required.

An object of the present invention is to provide a liquid refrigerant inflow prevention control method of the air conditioner for preventing the liquid refrigerant from flowing into the compressor as the temperature of the suction pipe of the compressor rapidly drops during the cooling operation.

In order to achieve the above object, the liquid refrigerant inflow prevention control method of the air conditioner according to the present invention, in the liquid refrigerant inflow prevention control method of the air conditioner, after starting the cooling operation of the air conditioner, the compressor for a predetermined time A first step of determining whether it is driven; A second step of determining a temperature of the compressor suction pipe when the predetermined time elapses; And when the temperature of the compressor suction pipe is less than a predetermined temperature, turn on the hot gas bypass valve 202 to supply a part of the hot gas discharged from the discharge pipe of the compressor to the accumulator 190, and If the temperature of the compressor suction pipe is not lower than the predetermined temperature, the hot gas bypass valve 202 is kept off to supply a part of the hot gas discharged from the discharge pipe of the compressor to the accumulator. It characterized in that it comprises a third step of preventing.

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In addition, in step 3, after the suction temperature of the compressor is determined to be less than the predetermined temperature and the hot gas bypass valve 202 is turned on, the temperature of the compressor suction pipe is a temperature higher than the predetermined temperature. The accumulator 190 is turned off by turning off the hot gas bypass valve 202 which is turned on when the temperature of the compressor discharge pipe exceeds T2 占 폚 or exceeds T3 占 폚, which is higher than the T2 占 폚. It characterized in that it further comprises the step of blocking the hot gas is supplied to).

Therefore, according to the present invention, since the liquid refrigerant flowing into the suction pipe of the compressor can be vaporized using hot gas discharged from the compressor, the liquid refrigerant flows into the compressor, so that the compressor is overloaded, the parts are burned out, and operation is performed. Problems such as not working can be prevented.

Hereinafter, with reference to the accompanying drawings, it will be described in more detail with respect to the liquid refrigerant inflow prevention control method of the air conditioner according to the present invention.

2 is an overall configuration diagram of a multi-type air conditioner according to an embodiment of the present invention, Figure 3 is a block diagram showing the configuration of an air conditioner for preventing the introduction of liquid refrigerant.

An indoor unit 140 having an indoor heat exchanger 142 and an indoor fan 144 is installed in the room, and the indoor unit 140 is connected to an outdoor unit 180 installed outside the room through a pipe. It is.

The outdoor unit 180 is equipped with a multi-type compressor composed of an inverter compressor 182 and a constant speed compressor 184. These compressors are devices for compressing and discharging a refrigerant circulating in an air conditioner at high temperature and high pressure. At the discharge end of the inverter compressor 182, an oil separator 186 for separating the refrigerant and the oil is mounted. The oil separator 186 is a device for separating oil discharged together with the refrigerant from the discharge end of the inverter compressor 182 from the refrigerant and then recycling the oil to the compressor. The oil contained in the oil separator 186 is a solenoid valve 187. ) And the bypass pipe 188 to the input terminal of the inverter compressor 182.

The refrigerant discharged at each discharge end of the compressors 182 and 184 passes through the oil separator 186, and after the oil contained therein is removed, the refrigerant discharged through the oil confluence pipe 189 merges in four directions. Inlet to (192). The four sides 192 is a device for changing the flow of the refrigerant flowing into or out of the compressors 182 and 184 according to each operation mode when the air conditioner is operated in the cooling or heating operation, in the case of the cooling operation The refrigerant flows in and out in the direction indicated by the solid arrows in FIG. 2, and the refrigerant flows in and out in the direction indicated by the dotted arrows in FIG. 2 in the heating operation. Therefore, the refrigerant discharged from the compressors 182 and 184 flows into the outdoor heat exchanger 194 in the case of a cooling operation and into the indoor unit 140 in the case of a heating operation.

One end of the outdoor heat exchanger 194 is connected to the four sides 192, the other end is connected to the electromagnetic expansion valve 162, respectively. Therefore, the refrigerant passing through the outdoor heat exchanger 194 and heat exchanged with the outdoor air passes through the electronic expansion valve (LEV) 162. The electronic expansion valve 162 expands the refrigerant under reduced pressure to convert it into a low temperature low pressure refrigerant. In this case, the refrigerant that is phase-converted to low temperature and low pressure while passing therethrough is introduced into the indoor unit 140 after passing through the receiver 164 and the dryer 166.

The low temperature low pressure refrigerant introduced into the indoor unit 140 lowers the temperature of the indoor (ie, air conditioning space) through heat exchange with the indoor air passing through the indoor heat exchanger 142 by the action of the indoor fan 144. .

Since the indoor unit 140 has one end connected to the four sides 192, the refrigerant having finished heat exchange through the indoor heat exchanger 142 flows to the four sides 192, and then is induced by the four sides 192. It enters an accumulator 190. The accumulator 190 is connected to the inlet of the inverter compressor 182 and the constant speed compressor 184, which is the liquid refrigerant is not vaporized into the compressors 182 and 184 while passing through the indoor unit 140 Serves to prevent this from happening.

Meanwhile, a compressor suction pipe temperature sensor 300 is mounted at the suction part of the accumulator 190 to adjust the temperature of the refrigerant flowing into the compressors 182 and 184 (this corresponds to the temperature of the compressor suction pipe). The discharge part of the compressors 182 and 184 is equipped with a compressor discharge pipe temperature sensor 302 to measure the temperature of the refrigerant discharged from the compressors 182 and 184 (which corresponds to the temperature of the compressor discharge pipe). Measure

Between the discharge pipe of the compressor and the suction pipe of the compressor, a hot for injecting a high-temperature, high-pressure refrigerant (hereinafter referred to as 'hotgas') discharged from the compressors 182 and 184 into the accumulator 190 A gas bypass pipe 200 is provided.

When the air conditioner operates at a low temperature cooling operation, the overall temperature of the refrigerant circulating in the cooling cycle gradually decreases, and eventually, unvaporized liquid refrigerant flows into the suction pipe of the compressor while passing through the indoor heat exchanger. The amount of these liquid refrigerants increases as the cooling operation continues at low temperatures, and the accumulator 190 is mounted to prevent the liquid refrigerant introduced into the suction pipe of the compressor from being sucked into the compressor.

When the liquid refrigerant is a small amount, the accumulation of the liquid refrigerant into the compressor by the accumulator 190 does not occur. However, in a case where the supercooling condition in which the amount of the liquid refrigerant exceeds the accumulator capacity continues, these liquid refrigerants overflowing the accumulator capacity flow into the compressor as it is, and the compressor is overloaded. A situation occurs or a part is burned out and the operation is stopped.

The hot gas bypass pipe 200 is installed to prevent such a situation, and when a large amount of liquid refrigerant flows into the suction pipe of the compressor to exceed the capacity of the accumulator 190, The hot gas discharged through the discharge pipe flows to the accumulator 190 to vaporize the liquid refrigerant accumulated in the accumulator 190 to be a refrigerant in the gas phase. Since the hot gas discharged to the discharge pipe of the compressor is a gas of high temperature and high pressure, when these hot gases are supplied to the accumulator 190, the low temperature liquid refrigerant is vaporized by the high temperature hot gas.

Therefore, according to the present invention, since the liquid refrigerant flowing in excess of the capacity of the accumulator 190 can be vaporized into the hot gas introduced through the hot gas bypass pipe 200, the liquid refrigerant remains in the compressor. Problems caused by the inflow can be prevented.

On the other hand, the hot gas bypass pipe 200 is equipped with a hot gas bypass valve 202 for controlling the opening and closing of the pipe. When the hot gas bypass valve 202 is off (ie, closed), the hot gas discharged from the compressors 182 and 184 to the compressor discharge pipe passes through the four sides 192 to the outdoor heat exchanger ( 194 and when the hot gas bypass valve 202 is on (ie, opened), some of the hot gases discharged from the compressors 182 and 184 to the compressor discharge line are As in the case where the valve is turned off, it is introduced into the four sides 192, and the rest is introduced into the accumulator 190 through the hot gas bypass pipe 200 and through the compressor suction pipe.

The on / off of the hot gas bypass valve 202 is controlled by the controller 400 of the air conditioner, and the temperature of the compressor suction pipe and the compressor discharge pipe temperature sensor 302 measured by the compressor suction pipe temperature sensor 300. The on / off of the valve is determined based on the temperature of the compressor discharge pipe measured in. In an embodiment of the present invention, if the temperature of the compressor suction pipe is less than T1 ° C., for example, 1 ° C., it is determined that excessive liquid refrigerant flows into the accumulator 190 and the hot gas bypass valve 202 is turned on. by turning on the hot gas into the accumulator 190, and when the temperature of the compressor suction pipe exceeds T2 ° C, for example 5 ° C, or the temperature of the compressor discharge pipe exceeds T3 ° C, for example 100 ° C, Turning off the pass valve 202 prevents hot gas from entering the accumulator 190.

At this time, since the temperature conditions for turning on / off the hot gas bypass valve 202 may be changed by the capacity of the compressor, the capacity of the accumulator, the hot gas bypass valve is opened when the liquid refrigerant is supplied excessively. It is a matter of course that the technical idea of the present invention that the gas is vaporized by supplying hot gas is not limited by the temperature conditions.

3 is a flowchart illustrating a liquid refrigerant inflow prevention control method of an air conditioner according to the present invention.

When the user operates the air conditioner by adjusting the key input of the air conditioner, the operation of the air conditioner is started while the outdoor fan, the indoor fan, and the compressor are started. When the air conditioner performs the cooling operation, the refrigerant reduces the temperature of the air conditioning space while circulating the cooling cycle of the compressor → outdoor heat exchanger → electromagnetic expansion valve → indoor heat exchanger → compressor.

As the cooling operation time of the low temperature is longer, the temperature of the refrigerant circulating in the cooling cycle gradually decreases, and the compressor suction pipe is cooled to maintain the liquid state of the refrigerant flowing into the suction pipe of the compressor. Therefore, in the present invention, after determining whether the compressor driving time has elapsed time t1 (step S100), if the compressor driving time has not exceeded t1 time, it is determined that the liquid refrigerant is not yet introduced into the compressor suction pipe and is not hot. The gas bypass valve is kept off (step S110), and if the compressor driving time exceeds t1 time, it is determined that the liquid refrigerant may flow into the compressor suction pipe and proceed to the next step.

The time t1 is, for example, about 1 minute, and as described above, in order for the liquid refrigerant to flow into the compressor suction pipe, it may take some time for the refrigerant to circulate the cooling cycle after the compressor is driven. In the embodiment, the time required for this circulation was determined to be about 1 minute, and this was regarded as a basic condition for turning on the hot gas bypass valve.

Subsequently, when it is determined in step S100 that the compressor driving time exceeds t1 time, it is next determined whether the temperature of the compressor suction pipe is less than T1 ° C, for example, 1 ° C (step S120). When the temperature of the compressor suction pipe is less than T1 ° C., it is determined that an excessive amount of liquid refrigerant may flow into the compressor suction pipe, so that the controller (400 of FIG. 3) turns on the hot gas bypass valve (202 of FIG. 2). (on) (S130) by supplying the hot gas discharged from the compressors to the accumulator (190 of FIG. 2) through the hot gas bypass pipe (200 of FIG. 2), the temperature of the compressor suction pipe is T1 ℃ If not, the controller (400 of FIG. 3) turns off the hot gas bypass valve (202 of FIG. 2) by determining that it is not yet a situation that an excessive amount of liquid refrigerant can be introduced into the compressor suction pipe. Keep (step S110).

When continuing the step S130 of supplying the hot gas discharged from the compressors to the accumulator, the temperature of the refrigerant flowing into the compressor by the hot gas is increased to reduce the cooling efficiency of the air conditioner. Therefore, the controller 400 of FIG. 3 should turn off the hot gas bypass valve 202 of FIG. 2 under appropriate conditions.

According to an embodiment of the present invention, when the temperature of the compressor suction pipe and the temperature of the compressor discharge pipe are read, and these temperatures satisfy a predetermined condition, it is determined that an excessive amount of liquid refrigerant flows into the compressor suction pipe is determined to have ended. Turn off the gas bypass valve.

Specifically, after the step S130, the control unit (400 of FIG. 3) determines whether the temperature of the compressor suction pipe exceeds T2 ℃, for example 5 ℃ (step S140), the temperature of the compressor suction pipe is T2 ℃ If it exceeds, it is determined that an excessive amount of liquid refrigerant can be introduced into the compressor suction pipe and the hot gas bypass valve (FIG. 2 of FIG. 2) is used to shut off the hot gas supplied to the accumulator (190 of FIG. 2). 202 is turned off (step S110).

However, if it is determined in step S140 that the temperature of the compressor suction pipe does not exceed T2 ° C., next, it is determined whether the temperature of the compressor discharge pipe exceeds T3 ° C., for example, 100 ° C. (S150). When it is read that the temperature exceeds T3 ° C, it is determined that the situation in which an excessive amount of liquid refrigerant can flow into the compressor suction pipe is ended, and the hot gas to block the hot gas supplied to the accumulator (190 in FIG. 2) is hot. The gas bypass valve 202 of FIG. 2 is turned off (step S110). On the other hand, if it is read that the temperature of the compressor discharge pipe does not exceed T3 ° C, it is determined that an excessive amount of liquid refrigerant can be introduced into the compressor suction pipe, and thus the accumulator is not finished yet. The hot gas bypass valve (202 of FIG. 2) is kept on in order to supply hot gas to the gas (190) (S130).

Therefore, according to the liquid refrigerant inflow prevention control method of the air conditioner according to the present invention, the hot gas bypass the high temperature and high pressure refrigerant (ie, hot gas) discharged from the compressor to the excessive amount of liquid refrigerant flowing into the compressor suction pipe By supplying vaporizer directly to the accumulator through piping, it is possible to solve the problem of liquid refrigerant flowing over the accumulator capacity.

On the other hand, in the liquid refrigerant inflow prevention control method of the air conditioner according to the present invention described above in FIG. 3 mentioned various values such as the compressor driving time (t1) of step S100, compressor suction piping temperature (T1 ℃) of step S120. These values may vary depending on the structure of the air conditioner, the capacity of the indoor unit, the capacity of the compressor, and the like, and it is apparent that the technical spirit of the present invention is not limited to these values.

According to the liquid refrigerant inflow prevention control method of the air conditioner according to the present invention, a hot gas bypass pipe and a hot gas bypass valve for controlling the opening and closing of the pipe between the discharge pipe of the compressor and the suction pipe of the compressor. Then, the excessive amount of liquid refrigerant flowing into the compressor suction pipe is supplied to the accumulator by vaporizing the high temperature and high pressure refrigerant (ie, hot gas) discharged from the compressor directly through the hot gas bypass pipe to vaporize the accumulator. It can solve the problem of liquid refrigerant flowing over the capacity.                     

As a result, the liquid refrigerant flows into the compressor, thereby preventing the compressor from being overloaded and causing parts to be burned out, thereby preventing operation.

Claims (3)

In the control method of preventing liquid refrigerant inflow of the air conditioner, A first step of determining whether the compressor has been driven for a predetermined time after the cooling operation of the air conditioner starts; A second step of determining a temperature of the compressor suction pipe when the predetermined time elapses; And When the temperature of the compressor suction pipe is less than a predetermined temperature, the hot gas bypass valve 202 is turned on to supply a part of the hot gas discharged from the discharge pipe of the compressor to the accumulator 190 and the compressor If the temperature of the suction pipe is not lower than the predetermined temperature, the hot gas bypass valve 202 is kept off to supply a part of the hot gas discharged from the discharge pipe of the compressor to the accumulator. And a third step of preventing the liquid refrigerant inflow preventing control method of the air conditioner. delete The method of claim 1, In the third step, after the suction temperature of the compressor is determined to be less than the predetermined temperature and the hot gas bypass valve 202 is turned on, the temperature of the compressor suction pipe is a temperature higher than the predetermined temperature. Or the accumulator 190 is turned off by turning off the hot gas bypass valve 202 which is turned on when the temperature of the compressor discharge pipe exceeds T3 ° C, which is higher than the T2 ° C. And preventing the hot gas from being supplied to the liquid refrigerant inflow preventing control method of the air conditioner.

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