KR100632023B1 - Driving control method of the hot gas bypass valve of an airconditioner - Google Patents

Abstract

The present invention relates to a method for controlling a hot gas bypass valve of an air conditioner, comprising: a first step of checking whether a compressor is in operation and a step of determining whether t2 time has elapsed after the compressor is stopped if it is determined that the compressor is not in operation. Step 2 and if the t2 time has not elapsed, turn on the hot gas bypass valve to discharge hot gas from the discharge side of the compressor to the suction side of the compressor, and if the t2 time has elapsed, the hot gas bypass And a third step of turning off the pass valve. Therefore, it is possible not only to reduce the starting current required for the initial startup of the compressor and to restart the compressor after stopping the compressor, but also to prevent a problem such as a compressor lock occurring when the compressor is restarted.

Air Conditioner, Hot Gas, Hot Gas Bypass Valve, Compressor, Restart

Description

Driving control method of the hot gas bypass valve of an airconditioner

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

2 is a general configuration diagram of a multi-type air conditioner according to an embodiment of the present invention having a hot gas bypass pipe.

3 is a flowchart illustrating a method for controlling a hot gas bypass valve of an air conditioner according to the present invention.

* Description of the symbols for the main parts of the 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

The present invention relates to a control method of an air conditioner, and more particularly, to a method for controlling a hot gas bypass valve of an air conditioner to quickly eliminate the pressure difference generated between the discharge side and the suction side of the compressor after the compressor is stopped. 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, in the case of the air conditioner, when the compressors 2 and 4 are driven and stopped, a considerably large pressure difference ΔP occurs between the pressure on the compressor discharge side and the pressure on the suction side, and this pressure difference is not completely removed. When the signal for restarting the compressor is inputted at (i.e., not in a flat pressure state), the starting current for restarting may increase due to the pressure difference ΔP, or a compressor lock may occur. have.

In order to solve the above-mentioned problem caused by the pressure difference between the discharge side pressure and the suction side pressure of the compressor upon restarting the compressor, normally, the compressor is not driven until the pressure difference ΔP naturally disappears and becomes the normal pressure. In this case, it takes about 30 minutes for the discharge side pressure and the suction side pressure of the compressor to become flat pressure. Therefore, the compressor does not immediately respond to changes in the load conditions, thereby reducing the efficiency of the air conditioner. Thrown away.

Accordingly, in order to solve various problems that occur when the compressor is restarted, research is being conducted on a method for quickly removing the pressure difference between the compressor discharge side and the suction side after the compressor is stopped.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for controlling a hot gas bypass valve of an air conditioner, by which the pressure difference generated between the discharge side and the suction side of the compressor can be quickly eliminated after the compressor is stopped.

In order to achieve the above object, the method for controlling a hot gas bypass valve of an air conditioner according to the present invention includes a first step of checking whether a compressor is in operation and a t2 time after the compressor is stopped if it is confirmed that the compressor is not in operation. The second step of judging whether the elapsed time has elapsed, and when the t2 time has not elapsed, the hot gas bypass valve is turned on to discharge the hot gas from the discharge side of the compressor to the suction side of the compressor, and when the t2 time has elapsed, And a third step of turning off the hot gas bypass valve.

On the other hand, in the first step, if it is determined that the compressor is in operation, it is preferable that the compressor further comprises the step of turning on the hot gas bypass valve until t1 time elapses after the start of the initial operation, the third step At, when the hot gas bypass valve is on, if a signal for restarting the compressor is input, it is preferable to further include the step of turning off the hot gas bypass valve after counting t3 time.

Therefore, according to the present invention, it is possible not only to reduce the starting current required for the initial start of the compressor and to restart the compressor after stopping the compressor, but also to prevent problems such as a compressor lock occurring when the compressor is restarted. have.

Hereinafter, a method for controlling a hot gas bypass valve of an air conditioner according to the present invention will be described in more detail with reference to the accompanying drawings.

First, Figure 2 is an overall configuration diagram of a multi-type air conditioner according to an embodiment of the present invention having a hot gas bypass pipe.

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 from 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 is combined 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. 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, between the discharge side pipe of the compressor and the suction side pipe of the compressor, the high temperature and high pressure refrigerant (hereinafter referred to as 'hot gas') discharged from the compressors 182 and 184 is discharged to the suction side pipe of the compressor. Hot gas bypass pipe (200) is installed.

When the air conditioner is operated under overload conditions such as overcooling and overheating, the pressure difference between the discharge side of the compressor and the suction side of the compressor becomes a high pressure above a certain pressure. When the compressor is stopped while such a pressure difference occurs, the discharge side of the compressor and the The pressure difference between the suction sides gradually becomes flat pressure over time while maintaining a high pressure state above the specific pressure.

At this time, if a signal for restarting the compressor is input before the discharge side pressure of the compressor and the suction side pressure of the compressor are equalized, the compressor is started in the presence of a predetermined pressure difference between the discharge side and the suction side. In this case, since the compression torque of the compressor is larger than the starting torque of the compressor, the starting load increases, the starting current of the compressor is excessively large, and the compressor lock occurs due to the high pressure.

Therefore, in order to solve the above problem, the air conditioner according to the present invention has provided a hot gas bypass pipe 200 between the discharge pipe of the compressor and the suction pipe of the compressor. The hot gas bypass pipe 200 is for discharging hot gas from the discharge side pipe of the compressor to the suction side pipe of the compressor. When the hot gas bypass pipe 200 is opened after the compressor is stopped, the compressor is discharged from the discharge side of the compressor. Since the high pressure hot gas is discharged to the suction side of, the pressure difference between the discharge side of the compressor and the suction side of the compressor becomes small within a short time. In other words, the compressor can be balanced within a short time after the compressor is stopped.

If the pressure difference between the discharge side and the suction side reaches a normal pressure within a short time after the compressor is stopped, the excessive starting current or the compressor lock caused by the pressure difference between the discharge side and the suction side of the compressor even if the compressor is restarted thereafter. Problems do not occur.

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 discharge side pipe of the compressor passes through the four sides 192 to the outdoor heat exchanger. 194 and when the hot gas bypass valve 202 is on (ie, opened), one of the hot gases discharged from the compressors 182 and 184 to the discharge side piping of the compressor Some flow into the four sides 192 as the valve is off, and the other flows through the hot gas bypass pipe 200 to the suction pipe (see arrow) of the compressor.

The on / off of the hot gas bypass valve 202 is controlled by a control unit (not shown) of the air conditioner. In one embodiment of the present invention, the compressor first controls the starting current at the time of starting the compressor and at the same time the compressor In order to enable a soft start of the compressor, it is turned on until t1 hours, for example, one minute, has elapsed since the initial operation of the compressor, and then the discharge side and the suction side of the compressor can reach a flat pressure within a short time. To this end, the compressor is turned on until t2 hours, e.g., 10 minutes have elapsed since the compressor stopped.

On the other hand, if the re-drive signal occurs after the compressor stops before the t2 time elapses, the control unit turns on the hot gas bypass valve 202 for t3 hours after restarting, for example, one minute, and then t3 hours When it elapses, it is immediately turned off. This is because the compressor is restarted in a state where the pressure is not reached, so that the hot gas bypass valve 202 is turned on for a predetermined time after the restart to control a low starting current that can be excessively flowed during the restart. to be.

The time conditions exemplified above to control the on / off of the hot gas bypass valve 202 may be changed by the capacity of the compressor, the capacity of the indoor unit, the external environment, etc., so that the pressure difference between the discharge side and the suction side of the compressor may be reduced. The technical idea of the present invention to reduce the starting current of the compressor by opening and adjusting the hot gas bypass valve is not limited by the time conditions exemplified above.

3 is a flowchart illustrating a method for controlling a hot gas bypass valve of an air conditioner according to the present invention.

In order to determine whether the process of lowering the pressure on the discharge side of the compressor should be performed by opening the hot gas bypass pipe (200 in FIG. 2) and supplying hot gas discharged from the compressor to the suction side pipe of the compressor, first, whether the compressor is in operation Check (S100 step).

Subsequently, when it is determined that the compressor is in operation, it is determined whether t1 time has elapsed since the compressor starts initial operation, that is, whether the elapsed time after the initial operation starts is t1 time, for example, less than 1 minute (step S110). .

The compressor performs a start operation for a predetermined time after the initial operation is started, and the current supplied to the compressor during this start operation is called a start current. Typically, the starting current is greater than the operating current when the compressor is operating normally. The starting current can be reduced by lowering the pressure on the discharge side of the compressor, that is, by reducing the starting load of the compressor. By reducing the starting load, the starting current can be reduced at the start of the compressor and the compressor is softly started. start).

In the present invention, in order to reduce the starting current of the compressor to reduce the starting current, the hot gas discharged from the discharge side of the compressor to the suction side of the compressor by turning on the hot gas bypass valve (202 in Fig. 2) during the initial operation of the compressor Supply to reduce the pressure on the discharge side of the compressor.

To this end, it is necessary to determine whether the operation state of the compressor is the initial operation state, the step S110 is a process that proceeds for this determination, if it is determined in step S110 that the compressor t1 time has not elapsed after the initial operation start. The controller (not shown) determines that the compressor is in a start-up operation, and turns on the hot gas bypass valve (202 in FIG. 2) to supply hot gas discharged to the discharge side of the compressor to the suction side of the compressor ( In step S120), when it is determined that the t1 time has elapsed since the initial operation of the compressor in step S110, the controller (not shown) determines that the compressor is not in the initial starting operation state, and thus the hot gas bypass valve (FIG. 2). By keeping the 202 of the off state (off), no further action is taken to reduce the starting current (step S170).

On the other hand, if it is determined in step S100 that the compressor is not in operation, it is determined whether the t2 time has elapsed since the compressor is stopped continuously, that is, whether the elapsed time after the compressor stops is t2, for example, less than 10 minutes (step S130). ). In this case, the t2 time is a reference time for determining whether the compressor discharge side and the suction side have achieved a flat pressure after the compressor is stopped, and when the t2 time has not elapsed since the compressor is stopped, the compressor has not yet reached the normal pressure. It is determined that the hot gas bypass valve (202 in Fig. 2) (on) (on step S140), and when the t2 time has elapsed after the compressor is stopped, it is determined that the compressor has reached a normal pressure and the hot gas The bypass valve 202 of FIG. 2 is turned off (step S170).

At this time, the hot gas bypass valve is turned on to discharge the hot gas from the discharge side of the compressor to the suction side of the compressor to lower the pressure on the discharge side of the compressor, that is, to restart the compressor while performing the step S140, which is a normal pressure process. When a signal is generated (step S150), the controller (not shown) counts t3 time, for example, 1 minute after the signal generation (step S160), and turns off the hot gas bypass valve (202 in FIG. 2). (S170 step). That is, when a signal for restarting the compressor is generated in the pressure equalizing process after the compressor is stopped, the hot gas bypass valve is turned off at the same time as t3 time elapses even if the pressure equalizing process is not completely terminated. This is to reduce the excessive starting load that occurs when the compressor is restarted during the equalizing process.

On the other hand, in step S150, if the compressor re-drive signal is not generated during the pressure equalization process, the steps S130, S140 and S170, etc. proceed according to the flowchart of FIG. 3 so that the hot gas bypass valve is turned off after the pressure equalization process ends. do.

According to the method for controlling the hot gas bypass valve of the air conditioner according to the present invention, first, by opening the hot gas bypass valve during the initial operation time of the compressor, the pressure on the discharge side of the compressor is lowered to reduce the starting current and at the same time the compressor is soft. The compressor can be started quickly, and then, by opening the hot gas bypass valve for a certain time after the compressor is stopped, the compressor can reach the normal pressure quickly.

Therefore, it is possible not only to reduce the starting current required for the initial startup of the compressor and to restart the compressor after stopping the compressor, but also to prevent problems such as a compressor lock occurring when the compressor is restarted.

Claims (3)

A first step of confirming whether the compressor is in operation; If it is confirmed that the compressor is not in operation, determining whether t2 time has elapsed after the compressor is stopped; And If the t2 time has not elapsed, the hot gas bypass valve is turned on to discharge hot gas from the discharge side of the compressor to the suction side of the compressor. If the t2 time has elapsed, the hot gas bypass valve is turned off. Hot gas bypass valve control method of an air conditioner, characterized in that it comprises a third step. The method of claim 1, In the first step, if it is confirmed that the compressor is in operation, the hot gas of the air conditioner further comprises the step of turning on the hot gas bypass valve until the time t1 elapses after the start of the initial operation of the compressor. How to control the bypass valve. The method of claim 1, In the third step, if a signal for restarting the compressor is input when the hot gas bypass valve is on, further comprising the step of turning off the hot gas bypass valve after counting t3 time. Hot gas bypass valve control method of the air conditioner.

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