Outdoor unit of air conditioner and method for controlling the same

1. An outdoor device for an air conditioning system, comprising:

a tank to store defrosting liquid;

a nozzle to apply defrosting liquid from the tank to a heat exchanger;

a valve to control flow of the defrosting liquid between the tank and nozzle;

a defrosting liquid tray to collect the defrosting liquid passing through the heat exchanger;

a concentration sensor provided in the defrosting liquid tray to detect a concentration of the collected defrosting liquid;

a defrosting liquid level sensor in the defrosting liquid tray to detect a liquid level of the collected defrosting liquid;

a supplement defrosting liquid tank to selectively supply supplement defrosting liquid to the tank;

a supplemental liquid valve having an adjustable opening degree to supply the supplement liquid into the tank from the supplement liquid tank; and

a controller to control the valve based on a temperature of the heat exchanger and a number of times the valve has been set to an open state during a heating mode of the air conditioning system, wherein the controller determines an amount required to fill the tank with the supplement defrosting liquid from the supplement defrosting liquid tank, on the basis of a concentration of a collected defrosting liquid detected by the concentration sensor, wherein the controller adjusts an opening degree of the supplement liquid valve when the concentration of the defrosting liquid detected by the concentration sensor is less than a predetermined concentration, and wherein the controller operates the pump to pump the defrosting liquid into the tank from the defrosting liquid tray, which is provided at a position lower than a position of the tank, when a liquid level of the defrosting liquid detected by the defrosting liquid level sensor is greater than a predetermined liquid level.

2. The outdoor device of claim 1 , wherein the controller controls the number of times the valve is set to the open state based on a comparison of the temperature of the heat exchanger to at least one predetermined temperature range.

3. The outdoor device of claim 2 , wherein the controller controls the valve to be open a first number of times when the temperature is in a first range, and a second number of times when the temperature is in a second range different from the first range.

4. The outdoor device of claim 3 , wherein the controller controls the valve to be open for a first time period for each of the first number of times and controls the valve to be open for a second time period for each of the second number of times, and wherein the first time period is different from the second time period.

5. The outdoor device of claim 4 , wherein a temperature of the first range is greater than a temperature of the second range, and the first time period is less than the second time period.

6. The outdoor device of claim 5 , wherein in the first temperature range the controller controls the valve to be in a second state for a period of time longer than the first period of time between the at least two of the first number of times.

7. The outdoor device of claim 6 , wherein the second state is a closed state.

8. The outdoor device of claim 6 , wherein the second state is between a fully open state and a fully closed state.

9. The outdoor device of claim 6 , wherein in the second temperature range the controller controls the valve to be in the second state for the second period of time between the at least two of the second number of times.

10. The outdoor device of claim 1 , wherein the controller controls information to be displayed indicating the level of defrosting liquid in the tank.

11. The outdoor device, of claim 10 , wherein the displayed information indicates that the tank needs to be refilled with defrosting liquid.

12. The outdoor device of claim 1 , wherein the temperature of the heat exchanger corresponds to a temperature of a surface of the heat exchanger or a temperature of air in a space in which the beat exchanger is located.