KR20050075099A - Linear expansion valve control method of a multi-type air conditioner - Google Patents

Abstract

The present invention relates to a control method of an electronic expansion valve of a multi-type air conditioner that improves the speed of converging room temperature to a set temperature and prevents temperature hunting, and comparing and measuring the room temperature and the set temperature. And calculating a temperature difference between the set temperature and the control pulse value for opening the electronic expansion valve if the temperature difference is large, and for opening the electronic expansion valve if the temperature difference is small. And gradually increasing or decreasing the control pulse value.

Description

Linear expansion valve control method of a multi-type air conditioner

The present invention relates to a control method of a multi-type air conditioner, and in particular, by varying the control pulse value for opening the electronic expansion valve according to the difference between the set temperature and the room temperature, improve the speed of convergence of the room temperature to the set temperature and temperature hunting The present invention relates to a control method of an electromagnetic expansion valve of a multi-type air conditioner.

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. It is not efficient in terms of space use only when a certain area of space is secured for each outdoor unit.

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 (3) for compressing a refrigerant, an outdoor heat exchanger (5) and a heat exchanger (5) for dissipating the compressed refrigerant. It is provided with the cooling fan 6 arrange | positioned at one side and accelerates heat dissipation of a refrigerant | coolant.

In the cooling operation, a main electromagnetic expansion valve 12 is provided downstream of the outdoor heat exchanger 5 along the flow direction of the refrigerant, and a refrigerant is provided at a downstream side of the main electromagnetic expansion valve 12. Sub solenoid expansion valves 13a, 13b, and 13c are provided to allow expansion under reduced pressure before they are introduced into 11b and 11c, respectively. First temperature sensors 15a, 15b, and 15c are provided to detect the temperature of the refrigerant discharged from 11a, 11b, and 11c.

Meanwhile, the constant speed compressor 3 and the inverter compressor 2 each have a compression capacity corresponding to half (50%) of the maximum air-conditioning load of the indoor unit 1, and each discharge side has a refrigerant having an outdoor heat exchanger 5. The second temperature detecting sensor 4 is joined to each other before being introduced into the first and second condensing zones. In addition, the inlet side of the compressor (2, 3) is provided with a third temperature sensor 17 to detect the temperature of the refrigerant flowing into the compressor.

Next, the cooling process of the multi-type air conditioner will be described.

The high temperature and high pressure gas refrigerant compressed by the compressors 2 and 3 is guided to the outdoor heat exchanger 5 by four sides (not shown), and then condensed in the process of passing through the outdoor heat exchanger 5 to obtain a high temperature and high pressure. Phase is changed by liquid refrigerant. The high temperature and high pressure liquid refrigerant from the outdoor heat exchanger (5) flows into the main electromagnetic expansion valve (12), and then passes through the sub solenoid expansion valves (13a, 13b, 13c) to a state of low temperature and low pressure, and then indoors. It flows into the heat exchangers 11a, 11b, 11c. At this time, the introduced refrigerant is converted into a gaseous refrigerant by evaporation, and guided to the suction side of the compressors 2 and 3 by four sides (not shown).

At this time, the refrigerant passing through the indoor heat exchangers (11a, 11b, 11c) takes heat away from the air in the room and evaporates, and thus the air conditioning space is repeatedly cooled and the temperature thereof decreases.

On the other hand, in order to adjust the control temperature of the air conditioning space, that is, the room temperature to the desired set temperature (that is, the target temperature) desired by the user, the rotation frequency of the inverter compressor 2 or the on / off of the constant speed compressor 3 to correspond to the total load amount. By controlling whether or not to control the compression capacity of the compressor, and accordingly to control the amount of refrigerant passing through each indoor heat exchanger (11a, 11b, 11c) by adjusting the opening degree of the electromagnetic expansion valve (13a, 13b, 13c) accordingly It is important.

The opening degree of the electromagnetic expansion valves 13a, 13b, and 13c is measured at each outlet measured by the first temperature sensor 15a, 15b, and 15c which senses the temperature of the refrigerant discharged from the indoor heat exchangers 11a, 11b, and 11c. The difference between the temperature value and the inlet temperature value measured by the third temperature sensor 17 which detects the temperature of the refrigerant flowing into the compressors 2 and 3 is controlled to maintain the set value (called 'superheat'). For example, if the difference between the outlet temperature value and the inlet temperature value is smaller than the set value, since the refrigerant may be introduced into the compressors 2 and 3 in a supercooled state, a pulse value for opening the electromagnetic expansion valves 13a, 13b, and 13c may be changed. By reducing the amount of refrigerant flowing into the indoor heat exchanger (11a, 11b, 11c) to solve the subcooled state, if the difference is greater than the set value, the indoor heat exchanger (11a, 11b, 11c) is overloaded so the electronic expansion Room heat by increasing the pulse value for opening the valves 13a, 13b, 13c By increasing the amount of refrigerant flowing into the vent (11a, 11b, 11c) to resolve the overload condition.

FIG. 2 is a graph illustrating a process in which the room temperature converges to a set temperature by a conventional electronic expansion valve control method, and illustrates a temperature pattern during heating operation.

After the user sets the desired room temperature and starts the operation of the air conditioner, the compressor calculates each actual load on each indoor heat exchanger and adjusts the compression capacity to correspond to the sum of the actual load, that is, the total load, The electronic expansion valve connected to each indoor heat exchanger determines an initial pulse value to adjust the amount of refrigerant flowing into each indoor heat exchanger based on the actual loads.

When the electromagnetic expansion valve determines the amount of refrigerant flowing into each indoor heat exchanger based on the initial pulse value, the refrigerant amount corresponding to the total load is discharged from the compressor, and the refrigerant amount corresponding to the actual load is introduced into each indoor heat exchanger. After the heat exchange with the indoor air (condensing action), the heat exchanged refrigerant is converted into a low temperature low pressure refrigerant through the electronic expansion valve, while the low temperature low pressure refrigerant is passed through the outdoor heat exchanger and the heating cycle of heat exchange (evaporation) with the outdoor air while repeating Start to raise the room temperature (part (a)).

Subsequently, when the room temperature is higher than the desired setting temperature and becomes overheated (see A), the controller decreases the pulse value for opening the electronic expansion valve by a predetermined value to reduce the amount of refrigerant flowing into each indoor heat exchanger. As the amount of refrigerant flowing into each indoor heat exchanger decreases, the room temperature becomes lower (part (b)).

Subsequently, when a certain time elapses while the pulse value of the solenoid expansion valve is decreased by a certain value (part (b)), the room temperature becomes lower than the set temperature desired by the user, so that the indoor heat exchanger is overloaded (see B). In this case, the controller increases the amount of refrigerant flowing into each of the indoor heat exchangers by increasing the pulse value for opening the electronic expansion valve to a predetermined value, and the room temperature increases as the amount of refrigerant increases (part (c)).

According to the conventional method of controlling the electromagnetic expansion valve, when the room temperature becomes higher than the desired setting temperature, the amount of refrigerant flowing into the indoor heat exchanger is decreased by a certain value by decreasing the pulse value of the electromagnetic expansion valve. When the temperature is lowered and the room temperature is lower than the set temperature, the pulse value is increased by a constant value to increase the amount of the refrigerant flowing into the indoor heat exchanger by raising the room temperature, thereby raising the room temperature. Attempts to converge with temperature.

However, according to the above-described conventional electronic expansion valve control method of reducing the amount of refrigerant flowing into each indoor heat exchanger when the indoor heat exchanger is overheated and increasing the amount of refrigerant when the indoor heat exchanger is overloaded, the difference between the room temperature and the set temperature is not significant. By constantly increasing or decreasing the control pulse value of the electronic expansion valve for the amount of refrigerant, regardless of the degree, it takes a lot of time to converge the room temperature to the desired set temperature, as shown in (d) of FIG. As shown in the drawing, the room temperature is hunted rather than converged to the set temperature.

An object of the present invention is to increase the speed of convergence of the room temperature to the set temperature and to prevent temperature hunting by varying the control pulse value for opening the electronic expansion valve according to the difference between the set temperature and the room temperature. It is to provide a control method of the valve.

The control method of the electronic expansion valve of the multi-type air conditioner according to the present invention for achieving the above object comprises the steps of measuring and comparing the room temperature and the set temperature, calculating a temperature difference between the room temperature and the set temperature; If the temperature difference is large, the control pulse value for the opening degree of the electromagnetic expansion valve is greatly increased or decreased, and if the temperature difference is small, the control pulse value for the opening degree of the electromagnetic expansion valve is slightly increased or decreased. Characterized in that.

According to an embodiment of the present invention, when the temperature difference is greater than 4 ° C, the control pulse value is increased or decreased by "8" pulses, and when the temperature difference is greater than 3 ° C and less than 4 ° C, the control pulse value is " 6 "pulse increase and decrease, if the temperature difference is greater than 2 ℃ and less than 3 ℃" 4 "pulse increase and decrease, if the temperature difference is greater than 1 ℃ and less than 2 ℃" control pulse value " It is preferable to increase or decrease the 2 " pulse and to increase or decrease the control pulse value by " 0 " pulse when the temperature difference is 1 占 폚 or less.

According to an embodiment of the present invention, in the heating operation, when the set temperature is higher than the room temperature, the control pulse value is increased corresponding to the temperature difference, and when the set temperature is not higher than the room temperature, the control is performed. The pulse value is reduced in correspondence with the temperature difference, and during cooling operation, when the set temperature is higher than the room temperature, the control pulse value is reduced in correspondence with the temperature difference, and when the set temperature is not higher than the room temperature It is preferable to increase the control pulse value corresponding to the temperature difference.

Therefore, according to the present invention, when the temperature difference between the room temperature and the set temperature is large, the control pulse value for opening the electromagnetic expansion valve is greatly increased or decreased, and when the temperature difference is small, the control for opening the electromagnetic expansion valve is small. Increase or decrease the pulse value in small widths. That is, when the temperature difference is large, the temperature difference can be reduced within a short time by greatly reducing or increasing the amount of the refrigerant flowing into the indoor heat exchanger, and when the temperature difference is small, Decrease or increase the amount in small increments to make the room temperature easier to converge to the set temperature.

Therefore, it is possible to improve the speed of convergence of the room temperature to the set temperature and to prevent temperature hunting.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the control method of the electromagnetic expansion valve of the multi-type air conditioner according to the present invention.

First, Figure 3 is an overall conceptual view of a multi-type air conditioner according to the present invention, Figure 4 is a block diagram showing a schematic configuration of a multi-type air conditioner according to the present invention.

The multi-type air conditioner according to the present invention is for controlling six rooms using two distributors, an outdoor unit 100, first and second distributors 102 and 110 connected to the outdoor unit 100, and each First to sixth indoor units 104, 106, 108, 112, 114, and 116 are provided for each room. The outdoor unit 100 and the first and second distributors 102 and 110 are connected to the main pipe P1, and the first distributor 102 and the first to third indoor units 104, 106 and 108 are respectively The first, second and third pipes P2, P3 and P4 are connected to each other, and the second distributor 110 and the fourth to sixth indoor units 112, 114, and 116 are respectively the fourth, fifth, and third pipes. 6 Connect with pipes (P5, P6 and P7).

At this time, the pipes P1 to P7 are insulated from each other in a pair of inflow pipes through which the refrigerant flows from the outdoor unit side to the indoor unit side, and outflow pipes through which the refrigerant flows from the indoor unit side to the outdoor unit side.

The outdoor unit 100 includes an inverter compressor, a constant speed compressor, an accumulator, a quadrilateral, an outdoor heat exchanger, an outdoor fan, and the like, and an outdoor controller 120 for controlling them, and the distributors 102 and 110 expand and expand the refrigerant under reduced pressure. Dispensing controllers 122 and 130 are provided for controlling the distribution of the electronic expansion valves and the refrigerant. The indoor units 104 to 116 are provided with an indoor heat exchanger, an indoor fan, and an indoor controller 124 to 136 for controlling them. It is.

When the user inputs a key for operating the air conditioner (cooling), the indoor controllers 124 to 136 installed in the one or more selected indoor units 104 to 116 can display the desired temperature, the current room temperature, the desired air volume, and the angle. After collecting data on the indoor unit capacity and the like and sending it to the outdoor controller 120, the outdoor controller 120 examines additional data such as the outdoor temperature to calculate the total load for operating the selected indoor units. This data is sent to the distribution controllers 122 and 130, and on the other hand, the compressors are driven based on it.

The refrigerant discharged by the driving of the compressor passes through the outdoor heat exchanger and then flows through the inlet pipe of the main pipe P1 to the first and second distributors 102 and 110, and flows through the first and second distributors 102. And the refrigerant introduced into the chamber 110 is expanded under reduced pressure while passing through the electronic expansion valves connected to the indoor heat exchangers of the respective chambers, and then each indoor unit 104 along the inflow pipes of the first to sixth pipes P2 to P7. To 116).

The refrigerant introduced into the indoor units 104 to 116 flows through an outlet pipe of the first to sixth pipes P2 to P7 after the heat exchanger passes through an indoor heat exchanger, and the first and second distributors 102 and 110. After being combined in, it is introduced into the outdoor unit 100 along the outlet pipe of the main pipe (P1).

The multi-type air conditioner according to the present invention employs a distributor between one outdoor unit and a plurality of indoor units. Conventionally, if one outdoor unit is to control six indoor units as described above, a total of 12 pipes of six inlet pipes and six outlet pipes should be installed to connect the outdoor unit to the indoor units of each room. The cost of plumbing was not low because it was not good and had to draw long pipes to the indoor unit.

However, in the case of the present invention, by adopting a distributor, a single pipe is installed from the outdoor unit to the outdoor unit, and each pipe is installed from the distributor to each indoor unit to improve the appearance by the single pipe. The cost problem was solved.

FIG. 5 is a configuration diagram of a refrigerant cycle of a multi-type air conditioner according to the present invention. In the multi-type air conditioner of FIG. 3 controlling six rooms using two distributors, the outdoor unit (100 in FIG. 3) and Only the part of 1 distributor (102 of FIG. 3) and the 1st-3rd indoor unit (104-108 of FIG. 3) is shown.

Each chamber of the room 140 includes a first, second, and third indoor heat exchanger 142a, 144a, and 146a and a first, second, and third indoor fan 142b, 144b, and 146b, respectively. And second and third indoor units 142, 144, and 146 are respectively provided.

The outdoor unit 180 includes a compression unit including an inverter compressor 182 and a constant speed compressor 184 for compressing and discharging the refrigerant at high temperature and high pressure, and the discharge parts of the compressors include a first oil supplier 186 for supplying oil and Second oil feeders 188 are provided respectively. The refrigerant discharged from the inverter compressor 182 and the constant speed compressor 184 pass through the first oil supplier 186 and the second oil supplier 188, respectively, and are combined to flow into the four sides 192.

The four sides 192 is a device for changing the flow of the refrigerant flowing into or out of the compressor according to each operation mode when the air conditioner is operated in the cooling or heating operation, in the case of the cooling operation is a solid line The refrigerant flows in and out in the direction of the arrow, and in the case of heating operation, the refrigerant flows in and out of the arrow direction indicated by the dotted line. Accordingly, the refrigerant discharged from the compressors 182 and 184 flows into the outdoor heat exchanger 194 in the case of cooling by the flow of the four sides 192, and in the case of heating, the first distributor ( 160).

The outdoor heat exchanger 194 is connected to the first distributor 160 through the inlet pipe 198a of the main pipe (P1 of FIG. 3), and in the case of cooling, discharged from the compressors 182 184. The high temperature and high pressure refrigerant serves as a condenser for radiating heat with the help of the outdoor fan 196, and in the case of heating, serves as an evaporator for absorbing outdoor heat.

The first distributor 160 has a first branch pipe 168 and a second branch pipe 170 therein, the first branch pipe 168 through the inlet pipe 198a of the main pipe. It is a tube for distributing the introduced refrigerant to each indoor unit, and the second branch pipe 170 is a tube for converging the refrigerant passing through each indoor unit into one place (in the case of heating, the opposite action).

Therefore, the inflow pipe 198a of the main pipe (P1 of FIG. 3) is the inflow pipe 163 of the 1st pipe (P2 of FIG. 3), and the 2nd piping (FIG. 3 of the said 1st branch pipe 168, respectively. The inlet pipe 165 of P3 and the inlet pipe 167 of the third pipe (P4 of FIG. 3) are branched, and the outlet pipe 198b of the main pipe (P1 of FIG. 3) is the second branch pipe 170. ), The outlet pipe 143 of the first pipe (P2 of FIG. 3), the outlet pipe 145 of the second pipe (P3 of FIG. 3), and the outlet pipe 147 of the third pipe (P4 of FIG. 3), respectively. Branched into

Inlet pipes 163, 165 and 167 of the first, second and third pipes are provided with first, second and third electromagnetic expansion valves 162, 164 and 166, respectively, which flow into each indoor unit. It is an apparatus for converting the refrigerant to be expanded under reduced pressure to a low temperature low pressure refrigerant. The refrigerant expanded under reduced pressure by the first to third electromagnetic expansion valves 162 to 166 may be the first to third indoor heat exchangers 142a to 146a through the inlet pipes 163 to 167 of the first to third pipes. ), The refrigerant exchanged through the first to third indoor heat exchangers (142a to 146a) and heat exchanged through the outlet pipes (143 to 147) of the first to third pipes, the second branch pipe (170). Flows into.

The second branch pipe 170 is connected to the four sides 192, and the refrigerant flowing out of the second branch pipe 170 is accumulated by the induction of the four sides 192 (see the solid arrow). It enters the accelerator 190. The accumulator 190 is connected to the inlets of the inverter compressor 182 and the constant speed compressor 184, and does not vaporize liquid while passing through the first, second and third indoor heat exchangers 142a, 144a, and 146a. The liquid refrigerant, which remains in the state, is prevented from entering the compressors 182 and 184.

The multi-type air conditioner according to the present invention is operated in a free joint method. The prejoint method is not a configuration method in which the refrigerant discharged from each compressor flows only a designated refrigerant cycle, but a configuration method in which the discharge parts of the compressor are combined into one such that any refrigerant cycle flows from the refrigerant discharged in each compressor. .

According to this, the frequency and operation method of the compressor can be adjusted as much as the required load, so power saving operation is possible, and economically advantageous because two small compressors are used instead of one large compressor.

3 to 5 illustrate a multi-type air conditioner that can control six indoor units using two distributors, for example, the number of distributors, the number of indoor units, and the type of indoor units (eg, ceiling type, frame type). Of course, the technical spirit of the present invention is not limited by the stand type or the like.

6 is a flowchart illustrating a control method of an electronic expansion valve of a multi-type air conditioner according to an embodiment of the present invention.

The control method of the electronic expansion valve according to the present invention includes the steps of: measuring and comparing the room temperature and the set temperature, and calculating the temperature difference between the room temperature and the set temperature; The control pulse value for opening the valve is greatly increased and decreased, and when the temperature difference is small, the control pulse value for opening the electromagnetic expansion valve is increased and decreased.

For example, in the heating operation, when the set temperature is greater than the room temperature, the control pulse value is increased corresponding to the temperature difference. When the set temperature is not greater than the room temperature, the control pulse value is increased to the temperature difference. Correspondingly decrease. On the other hand, in the cooling operation, as opposed to the heating operation, when the set temperature is greater than the room temperature, the control pulse value is reduced corresponding to the temperature difference, and when the set temperature is not greater than the room temperature, the control pulse value is decreased. It increases in response to the temperature difference.

Hereinafter, an embodiment of the control method of the electromagnetic expansion valve according to the present invention will be described in detail, for example, during heating operation.

After the user sets the desired room temperature and starts the operation of the multi-type air conditioner according to the present invention, the compressor (182, 184 of FIG. 5) calculates the actual load applied to each indoor heat exchanger, and then adds the calculated values. That is, the compression capacity is adjusted to correspond to the total load, and the electromagnetic expansion valves (162, 164, and 166 of FIG. 5) connected to each indoor heat exchanger (142a, 144a, and 146a of FIG. 5) are based on the actual loads. The initial pulse value is determined to control the amount of refrigerant flowing into the indoor heat exchanger.

When the electronic expansion valves 162, 164, and 166 of FIG. 5 determine the amount of refrigerant flowing into each indoor heat exchanger based on the initial pulse value, the amount of refrigerant corresponding to the total load is determined by the compressor (182, 184 of FIG. 5). ), The refrigerant amount corresponding to the actual load is introduced into each indoor heat exchanger (142a, 144a, and 146a of FIG. 5), and then heat exchanged with the indoor air (condensing action), and the heat exchanged refrigerant is transferred to the electronic expansion valve (see FIG. 5). 162, 164, 166 to convert to a low temperature low pressure refrigerant, the low temperature low pressure refrigerant through an outdoor heat exchanger (194 in Fig. 5) while repeating the heating cycle of heat exchange with the outdoor air (evaporation) while increasing the room temperature Let's start.

Meanwhile, in the process of repeating the heating cycle, the process of periodically comparing the room temperature of the air conditioning space and the set temperature desired by the user is repeated, which measures the change of the actual load from time to time and correspondingly compresses the compressor. And to adjust the opening degree of the electromagnetic expansion valve for each seal load. In an embodiment of the present invention, after comparing the room temperature with the set temperature (step S100), if the set temperature is greater than the room temperature, the temperature difference is calculated by subtracting the room temperature value from the set temperature value (step S102). If the set temperature is not greater than the room temperature, the temperature difference is calculated by subtracting the set temperature value from the room temperature value (step S104).

In this case, the large temperature difference between the room temperature and the set temperature means that the indoor heat exchanger is overheated or the degree of the load placed on the indoor heat exchanger is significant, and the small temperature difference means that the indoor heat exchanger is overheated. B means that the degree of load is relatively small.

Therefore, in the present invention, the control pulse value for opening the electromagnetic expansion valve is also changed according to the degree of the temperature difference. First, it is determined whether the temperature difference is 1 ° C. or less (step S106), and the temperature difference is 1 ° C. or less. The control pulse value for opening the electronic expansion valve is increased or decreased by "0" pulse (increase when the set temperature is greater than the room temperature and decrease when the set temperature is not greater than the room temperature) (step S108). The temperature difference is less than 1 ℃ because it can be determined that the room temperature is close to the set temperature converged because it is not necessary to increase or decrease the amount of refrigerant flowing into the indoor heat exchanger. Therefore, when the temperature difference is 1 ° C. or less, the control pulse value for opening the electromagnetic expansion valve is increased or decreased by “0” to maintain the amount of refrigerant flowing into the indoor heat exchanger.

On the other hand, in step S106, after determining whether the temperature difference is not less than 1 ℃ or less, that is, 1 ℃ <temperature difference ≤ 2 ℃ (step S110), when the temperature difference is less than 2 ℃, The control pulse value for opening the electromagnetic expansion valve is increased or decreased by "2" pulses. That is, if the set temperature is greater than the room temperature, the pulse "2" is increased, and if the set temperature is not greater than the room temperature, the pulse "2" is decreased (step S112). The temperature difference of less than 2 ℃ can be determined that the room temperature is just before the convergence slightly higher or lower than the set temperature, so that the amount of refrigerant flowing into the indoor heat exchanger is slightly reduced or increased accordingly to converge the room temperature to the set temperature. .

Subsequently, in the step S110, if it is determined that the temperature difference is not 2 ° C or less, or 3 ° C or less, that is, 2 ° C <temperature difference ≤ 3 ° C (step S114), when the temperature difference is 3 ° C or less The control pulse value for opening the electromagnetic expansion valve is increased or decreased by "4" pulses. That is, if the set temperature is greater than the room temperature, the "4" pulse is increased, and if the set temperature is not greater than the room temperature, the "4" pulse is decreased (step S116). When the temperature difference is 3 ° C. or less, the room temperature is 3 ° C. higher or lower than the set temperature so that a person in the air conditioning space may feel that the room temperature has not yet converged to the set temperature. Therefore, according to an embodiment of the present invention, when the room temperature is about 3 ° C. higher than the set temperature, the control pulse value for opening the electromagnetic expansion valve is reduced by about 4 pulses to reduce the amount of refrigerant flowing into the indoor heat exchanger. When the room temperature is lowered and the room temperature is about 3 ° C. lower than the set temperature, the control pulse value for opening the electromagnetic expansion valve is increased by about 4 pulses to increase the amount of refrigerant flowing into the indoor heat exchanger. Increase the temperature

Subsequently, in step S114, if the temperature difference is not 3 ° C or less, or after determining whether it is 4 ° C or less, that is, 3 ° C <temperature difference ≤ 4 ° C (step S118), and when the temperature difference is 4 ° C or less, Increase or decrease the control pulse value for opening the solenoid expansion valve by "6" pulses (i.e., increase "6" pulses if the set temperature is greater than room temperature, or "6" pulses if the set temperature is not greater than room temperature. (Step S120), if the temperature difference is greater than 4 ° C, increase or decrease the control pulse value for opening the electromagnetic expansion valve by " 8 " (i.e., if the set temperature is greater than room temperature). &Quot; Increase the pulse, and decrease the " 8 " pulse when the set temperature is not greater than the room temperature (step S122). The amount of the refrigerant flowing into the indoor heat exchanger is increased or decreased corresponding to the control pulse value.

In the control method of the electromagnetic expansion valve according to the present invention, when it is determined that the indoor heat exchanger is overheated regardless of the difference between the room temperature and the set temperature, the control pulse value for the opening degree of the electromagnetic expansion valve is decreased by a certain value. If it is determined that the indoor heat exchanger is overloaded, repeat the process of increasing or decreasing the amount of refrigerant flowing into the indoor heat exchanger by increasing the control pulse value for opening the solenoid expansion valve to a predetermined value. Unlike the conventional method of converging, when the difference between the room temperature and the set temperature is large, the control pulse value for opening the electromagnetic expansion valve is increased, and when the difference between the room temperature and the set temperature is small, the control pulse. The value is also small so that the amount of refrigerant flowing into the indoor heat exchanger depends on the degree of temperature difference. Do it differently.

Therefore, according to the present invention, when the temperature difference between the room temperature and the set temperature is large, the temperature difference can be reduced in a short time by greatly reducing or increasing the amount of the refrigerant flowing into the indoor heat exchanger. In small cases, the room temperature tends to converge to the set temperature by reducing or increasing the amount of refrigerant flowing into the indoor heat exchanger in small widths.

On the other hand, in Fig. 6, when the temperature difference between the room temperature and the set temperature is greater than 4 ° C, the control pulse value is "8" pulse. Although the control pulse value is also determined and shown for each temperature difference such as a 6 "pulse, the control pulse value is relatively large when the temperature difference is large, and the control pulse value is adjusted accordingly when the temperature difference is small. If the basic technical idea is included, it is obvious that even if the control pulse value according to the temperature difference is slightly changed, it can be determined as an embodiment of the present invention.

In addition, in the description of the technical idea of the present invention with reference to FIG. 6, the heating operation is described as an example. However, in the case of the cooling operation, when the temperature difference between the room temperature and the set temperature is large, The principle that the control pulse value is greatly increased and decreased, and the control pulse value is increased or decreased when the temperature difference is small can be easily applied to those skilled in the art. Of course it can be expected.

For example, in a cooling operation, when the set temperature is greater than the room temperature, when the temperature difference is greater than 4 ° C, the control pulse value is decreased by "8" pulses, and the temperature difference is greater than 3 ° C and less than 4 ° C. Y decreases the control pulse value by "6" pulses, and decreases the control pulse value by "4" pulses when the temperature difference is greater than 2 ° C and less than 3 ° C. The control pulse value is reduced by " 2 " pulses, and the control pulse value is reduced by " 0 " pulses when the temperature difference is 1 占 폚 or less.

Conversely, if the set temperature is less than room temperature, the control pulse value is increased by " 8 " pulses if the temperature difference is greater than 4 ° C, and the control pulse if the temperature difference is greater than 3 ° C and less than 4 ° C. Increase the value by "6" pulses, and increase the control pulse value by "4" pulses when the temperature difference is greater than 2 ° C and below 3 ° C; The value is increased by "2" pulses, and the control pulse value is increased by "0" pulses when the temperature difference is 1 ° C or less.

7 is a graph illustrating a process in which the room temperature converges to a set temperature by the electronic expansion valve control method according to an exemplary embodiment of the present invention, and illustrates a temperature pattern during heating operation.

After the user sets the desired room temperature and starts the operation of the air conditioner, the compressor calculates each actual load on each indoor heat exchanger and adjusts the compression capacity to correspond to the sum of the actual load, that is, the total load, The electronic expansion valve connected to each indoor heat exchanger determines an initial pulse value to adjust the amount of refrigerant flowing into each indoor heat exchanger based on the actual loads.

When the electromagnetic expansion valve determines the amount of refrigerant flowing into each indoor heat exchanger based on the initial pulse value, the refrigerant amount corresponding to the total load is discharged from the compressor, and the refrigerant amount corresponding to the actual load is introduced into each indoor heat exchanger. After the heat exchange with the indoor air (condensing action), the heat exchanged refrigerant is converted into a low temperature low pressure refrigerant through the electronic expansion valve, while the low temperature low pressure refrigerant is passed through the outdoor heat exchanger and the heating cycle of heat exchange (evaporation) with the outdoor air while repeating Start to raise the room temperature (part (a)).

At this time, the controller periodically determines the difference between the current room temperature and the set temperature. When the room temperature is determined to be an overheated state (see A), for example, higher than the desired temperature, for example, 4 ° C., the electronic expansion is performed. The control pulse value for the valve opening is reduced to about "8" pulses, which greatly reduces the amount of refrigerant flowing into the indoor heat exchanger. Therefore, the room temperature is lowered at a rapid rate with the decrease in the amount of refrigerant (part (b)).

The controller continues to calculate the difference between the current room temperature and the set temperature in the process of decreasing the amount of refrigerant and decreasing the room temperature ((b)). For example, if the room temperature is lower than 4 ° C. below the desired setting temperature and is determined to be an overload condition (see B), the control pulse value for opening the solenoid valve is reduced to about 6 pulses. The amount of refrigerant flowing into the indoor heat exchanger is greatly increased. Therefore, the room temperature is rapidly increased with the increase of the amount of refrigerant ((c) part).

Subsequently, periodically determining the difference between the room temperature and the set temperature, and increasing or decreasing the control pulse value for the opening of the electromagnetic expansion valve based on the temperature difference obtained in the determining step. The step of adjusting the amount of the refrigerant is carried out, and as the steps are repeated, the difference between the room temperature and the set temperature is drastically reduced, and finally, the room temperature converges to the set temperature (part (d)).

Referring to FIG. 7, it can be seen that the time taken for the room temperature to converge near the set temperature and stabilize after the operation of the air conditioner is much shorter than in the related art (see T1 in FIG. 2) (see T2). In the stable section, the room temperature is hunted without convergence to the set temperature, but in the present invention, the hunt is converged to the set temperature without hunting.

According to the electronic expansion valve control method of the multi-type air conditioner according to the present invention, when the temperature difference between the room temperature and the set temperature is large, the control pulse value for opening the electromagnetic expansion valve is greatly increased and decreased, and the temperature difference is small. In this case, the control pulse value for opening the electromagnetic expansion valve is increased or decreased in a small width.

That is, when the temperature difference is large, the temperature difference can be reduced within a short time by greatly reducing or increasing the amount of the refrigerant flowing into the indoor heat exchanger, and when the temperature difference is small, Decrease or increase the amount in small increments to make the room temperature easier to converge to the set temperature.

Therefore, it is possible to improve the speed of convergence of the room temperature to the set temperature and to prevent temperature hunting.

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

2 is a graph illustrating a process in which the room temperature converges to a set temperature by a conventional electronic expansion valve control method.

3 is an overall conceptual diagram of a multi-type air conditioner according to the present invention.

4 is a block diagram showing a schematic configuration of a multi-type air conditioner according to the present invention.

5 is a configuration diagram of a refrigerant cycle of the multi-type air conditioner according to the present invention.

6 is a flowchart illustrating a control method of an electromagnetic expansion valve of a multi-type air conditioner according to an embodiment of the present invention.

7 is a graph illustrating a process in which the room temperature converges to a set temperature by the electronic expansion valve control method according to an exemplary embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

100, 180: outdoor unit 102, 160: first distributor

110: second distributor 104, 142: first indoor unit

106, 144: Second indoor unit 108, 146: Third indoor unit

142a: first indoor heat exchanger 144a: second indoor heat exchanger

146a: third indoor heat exchanger 162: first electromagnetic expansion valve

164: second electromagnetic expansion valve 166: third electromagnetic expansion valve

168: first branch pipe 170: second branch pipe

182: inverter compressor 184: constant speed compressor

190: Accumulator 192: Four sides

194: outdoor heat exchanger P1: main pipe

P2, P3, P4, P5, P6, P7: 1st, 2, 3, 4, 5, 6 Piping

Claims (5)

Measuring and comparing the room temperature and the set temperature; Calculating a temperature difference between the room temperature and the set temperature; And If the temperature difference is large, the control pulse value for the opening degree of the electromagnetic expansion valve is greatly increased or decreased, and if the temperature difference is small, the control pulse value for the opening degree of the electromagnetic expansion valve is slightly increased or decreased. The control method of the electronic expansion valve of the multi-type air conditioner, characterized in that. The method of claim 1, If the temperature difference is greater than 4 ° C, the control pulse value is increased or decreased by "8" pulses. If the temperature difference is greater than 3 ° C and is less than 4 ° C, the control pulse value is increased or decreased by "6" pulses. Is greater than 2 ° C. and less than or equal to 3 ° C., increases or decreases the control pulse value by “4” pulses. If the temperature difference is greater than 1 ° C. and is less than or equal to 2 ° C., increases or decreases the control pulse value to “2” pulses. When the control pulse value is 1 ° C. or lower, increasing or decreasing the control pulse value by “0” pulses. The method of claim 1, In the heating operation, when the set temperature is higher than the room temperature, the control pulse value is increased in response to the temperature difference, and when the set temperature is not higher than the room temperature, the control pulse value is corresponding to the temperature difference. In the cooling operation, when the set temperature is higher than the room temperature, the control pulse value is decreased corresponding to the temperature difference, and when the set temperature is not higher than the room temperature, the control pulse value is reduced to the temperature difference. And correspondingly increasing, the control method of the electromagnetic expansion valve of the multi-type air conditioner. The method of claim 1, In the heating operation, when the set temperature is greater than the room temperature, the control pulse value is increased by " 8 " pulses when the temperature difference is greater than 4 ° C, and the control when the temperature difference is greater than 3 ° C and 4 ° C or less. Increase the pulse value by " 6 " pulses and increase the control pulse value by " 4 " pulses when the temperature difference is greater than 2 &lt; The pulse value is increased by 2 pulses, and when the temperature difference is 1 ° C. or less, the control pulse value is increased by 0 pulses. The method of claim 1, In the heating operation, when the set temperature is not greater than the room temperature, when the temperature difference is greater than 4 ° C, the control pulse value is decreased by "8" pulses, and when the temperature difference is greater than 3 ° C and less than 4 ° C, Decreases the control pulse value by "6" pulses, and decreases the control pulse value by "4" pulses when the temperature difference is greater than 2 ° C and below 3 ° C; The control pulse value is reduced by "2" pulses, and the control pulse value is reduced to "0" pulses when the temperature difference is less than 1 ℃, the control method of the electronic expansion valve of the multi-type air conditioner.