Air conditioning system and method for operating the same

• US 6,807,815 B2
• Filed: 03/04/2003
• Issued: 10/26/2004
• Est. Priority Date: 06/19/2002
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Huh, Deok, Kim, Cheol Min, Lee, Won Hee, Choi, Chang Min, Hwang, Yoon Jei
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US10/377,779
• Publication Number:
  US 20030233837A1
• Time in Patent Office: 602 Days
• Field of Search: 622/31, 621/75, 621/58, 236/1.EA, 236/49.3
• US Class Current: 62/158
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/02331 during cooling
• CPC Class Codes: F25B 2313/02334 during heating
• CPC Class Codes: F25B 2400/0751 the compressors having different capacities
• CPC Class Codes: F25B 2500/19 Calculation of parameters
• CPC Class Codes: F25B 2600/02 Compressor control
• CPC Class Codes: F25B 2700/2104 of an indoor room or compartment
• CPC Class Codes: F25B 49/022 Compressor control arrangements

Abstract

An air conditioning system and a method for operating the air conditioning system, in which a plurality of compressors are simultaneously or selectively operated, based on the difference between a room temperature and a desired temperature generated during a waiting time for re-operation of the compressors. The room temperature varying during the waiting time for the re-operation of the compressors maintained at a stopped state is sensed to determine whether or not an increase in cooling load occurs. Based on the amount of the cooling load, it is determined whether the compressors have to operate simultaneously or selectively. That is, the refrigerant compression capacity of the air conditioning system is determined by reflecting the cooling load caused by a variation in room temperature occurring during the waiting time for re-operation taken until any compressor maintained in a stopped state is re-operated. Accordingly, it is possible to more stably control the room temperature, and to achieve an improvement in the comfortableness of the room atmosphere.

Claims

1. An air conditioning system comprising:

an air conditioner for establishing a cooling cycle adapted to sequentially perform compression, condensation, expansion and evaporation functions, and eliminating a cooling load in a room by the cooling cycle, thereby conditioning the atmosphere of the room;

a control unit for controlling an operation state of a compressor unit adapted to perform the compression function, in order to vary a refrigerant compression capacity of the compressor unit in accordance with the cooling load,

wherein the air conditioner comprises;

the compressor unit including a plurality of compressors each adapted to compress a low-temperature and low-pressure gaseous refrigerant, thereby changing the refrigerant into a high-temperature and high-pressure state;

a condenser adapted to condense the high-temperature and high-pressure gaseous refrigerant, thereby changing the refrigerant into a medium-temperature and high-pressure liquid refrigerant;

an expansion valve adapted to reduce the pressure of the medium-temperature and high-pressure liquid refrigerant emerging from the condenser, thereby changing the liquid refrigerant into a low-temperature and low-pressure liquid refrigerant; and

an evaporator adapted to evaporate the low-temperature and low-pressure liquid refrigerant emerging from the expansion valve, thereby changing the liquid refrigerant into a low-temperature and low-pressure gaseous refrigerant; and

wherein the control unit comprises;

a counting unit senses that a point of time when the compressor unit is stopped, and counts a waiting time taken until the stopped compressor unit is re-operated;

a temperature sensing unit that senses a temperature of the room after the waiting time counted by the counting unit;

a load determining unit that determines a cooling load generated during the waiting time, based on a temperature difference between the room temperature sensed by the temperature sensing unit and a previously-input desired temperature; and

a compressor controlling unit that outputs a control signal making the compressor unit operate in a full operation mode or a selective operation mode in accordance with the cooling load sensed by the load determining unit.

2. The air conditioning system according to claim 1, wherein the load determining unit determines whether or not the temperature difference is more than a predetermined value, and determines an abrupt increase in cooling load when it is determined that the temperature difference is more than the predetermined value.

3. A method for operating an air conditioning system comprising:

simultaneously operating a plurality of compressors included in the air conditioning system until a temperature of a room to be cooled reaches a predetermined temperature;

stopping the operation of the compressors when the room temperature reaches the predetermined temperature, and sensing a temperature of the room after a waiting time taken until the stopped compressors are re-operated; and

simultaneously or selectively operating the compressors in accordance with a temperature difference between the room temperature sensed at the stopping and sensing and the predetermined temperature.

4. The method according to claim 3, wherein the simultaneously or selectively operating comprises:

calculating the temperature difference between the room temperature sensed at the stopping and sensing and the predetermined temperature; and

determining whether or not the temperature difference calculated at the calculating is less than a predetermined value, and simultaneously or selectively operating the compressors, based on the result of the determination.

5. The method according to claim 4, wherein the determining and simultaneously or selectively operating comprises selectively operating the compressors when the temperature difference is less than the predetermined value, while simultaneously operating the compressors when the temperature difference is not less than the predetermined value.