Control method of an air conditioner indoor unit

A control method of a multi-air conditioner in which a plurality of indoor units is connected to one outdoor unit and refrigerant flow amount is adjusted by electronic expansion valves comprises a share step in which a plurality of indoor units exchanges their operation information, a comparison and judgment step in which each above indoor unit compares and judges its operation status based on the exchanged operation information, and an adjustment step in which each above indoor unit adjusts refrigerant flow amount supplied to each indoor unit based on the compared and judged operation status.

This application claims the benefit of the Patent Korean Application No. P2004-105328, filed on Dec. 14, 2004, which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air conditioner, and more particularly, to a control method of a multi-air conditioner indoor unit.

2. Discussion of the Related Art

Generally, an air conditioner is an apparatus cooling/heating a room by the process of compressing, condensing, expanding and evaporating a refrigerant.

The air conditioner is classified into a cooling system in which a refrigerant cycle is operated only in one direction to supply cold air to the room, and a cooling/heating system in which a refrigerant cycle is selectively operated in bilateral direction to supply cold air or warm air the room.

The air conditioner is also classified into an air conditioner in which one indoor unit is connected to one outdoor unit, and a multi-air conditioner in which a plurality of indoor units is connected to one outdoor unit.

However, in conventional multi-air conditioners, each indoor unit performs sending and receiving with one outdoor unit, therein causing a problem that each indoor unit may not have the equalized capability of cooling/heating.

Even indoor units with same capacity may cause capability variation of an indoor heat exchanger, when indoor units are different models. Also although indoor units are the same models, capability variation may arise among indoor units according to the conditions in which each indoor unit is installed such as length of the pipes connected to one outdoor unit, height of the pipes, shape of the pipes branched out from one outdoor unit.

The above capability variation of each indoor unit deteriorates cooling/heating efficiency of a multi-air conditioner.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a control method of a multi-air conditioner indoor unit that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a control method of a multi-air conditioner indoor unit capable of enhancing cooling/heating efficiency by preventing capability variation among indoor units through adjusting refrigerant flow amount supplied to each indoor unit according to the capability of a plurality of indoor units connected to one outdoor unit.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a multi-air conditioner in which a plurality of indoor units are connected to one outdoor unit comprises a share step in which a plurality of indoor units exchanges and share its operating information; a comparison and judgment step in which each above indoor unit compares and judges its operation status based on the operation information exchanged among the indoor units; an adjustment step in which the refrigerant flow amount supplied to each above indoor unit is adjusted, according to the operation status compared and judged by the each above indoor unit.

A confirmation step is further comprised in which each above indoor unit confirms that each indoor unit receives operation information from the other indoor units.

The share step comprises a calculation step in which performance ratio of each indoor unit is calculated; and a mutual send/receive step in which each indoor unit sends/receives each performance ratio.

The above calculation step is calculated based on inlet air temperature value, outlet air temperature value, and air amount value of each indoor unit.

The comparison and judgment step distinguishes indoor units which have less than 1 performance ratio and indoor units which have more than 1 performance ratio from the indoor units.

In the comparison and judgment step, it is preferred but not necessary that the adjustment step be performed in case that there are at least one indoor unit with less than 1 performance ratio and at least one indoor unit with more than 1 performance ratio.

Thus, according to the comparison and judgment step, the indoor unit with more than 1 performance ratio is adjusted to decrease the refrigerant amount and the indoor unit with less than 1 performance ratio is adjusted to increase the refrigerant amount.

The performance ratio is the present outlet performance ratio for regular capability of the indoor unit.

In the adjustment step, the refrigerant amount supplied to each indoor unit is adjusted by a sub-electronic expansion valve provided between each indoor unit and an electronic expansion valve.

In another aspect of the present invention, a multi-air conditioner in which a plurality of indoor units is connected to one outdoor unit comprises a share step in which a plurality of indoor units sends/receives its outlet air temperature value and exchanges and shares its operating information; a comparison and judgment step in which each above indoor unit compares and judges its operation status based on the operation information exchanged among the indoor units; an adjustment step in which the refrigerant flow amount supplied to each above indoor unit is adjusted, according to the operation status compared and judged by the each above indoor unit.

The comparison and judgment step comprises a calculation step in which each indoor unit collects its outlet air temperature value to calculate average outlet air temperature value and a comparison step in which the average outlet air temperature value and the outlet air temperature value are compared

In the comparison and judgment step, the adjustment step may be performed in case that there are at least one indoor unit which has lower outlet air temperature value than average outlet air temperature value and at least one indoor unit which has higher outlet air temperature value than average outlet air temperature value.

After the performance of the comparison and judgment step, the refrigerant amount supplied to the indoor unit which has lower outlet air temperature value than average outlet air temperature value is adjusted when the multi-air conditioner performs cooling. The refrigerant amount supplied to the indoor unit which has higher outlet air temperature value than average outlet air temperature value is adjusted when the multi-air conditioner performs heating.

In the adjustment step, the refrigerant amount supplied to each indoor unit is adjusted by a sub-electronic expansion valve provided between each indoor unit and each electronic expansion valve.

In another aspect of the present invention, a multi-air conditioner in which a plurality of indoor units is connected to one outdoor unit comprises a share step in which a plurality of indoor units sends/receives its each pipe temperature value and exchanges and shares its operating information; a comparison and judgment step in which each above indoor unit compares and judges its operation status based on the operation information exchanged among the indoor units; an adjustment step in which the refrigerant flow amount supplied to each above indoor unit is adjusted, according to the operation status compared and judged by the each above indoor unit.

The comparison and judgment step comprises a calculation step in which each indoor unit collects its pipe temperature value to calculate average pipe temperature value; a comparison step in which the average pipe temperature value and the pipe temperature value are compared.

In the comparison and judgment step, the adjustment step may be performed in case that there are at least one indoor unit which has lower pipe temperature value than average pipe temperature value, and a least one indoor unit which has higher pipe temperature value than average pipe temperature value.

After the performance of the comparison and judgment step, the refrigerant amount supplied to the indoor unit which has lower pipe temperature value than average pipe temperature value is adjusted when the multi-air conditioner performs cooling. The refrigerant amount supplied to the indoor unit which has higher pipe temperature value than average pipe temperature value is adjusted when the multi-air conditioner performs heating.

In the adjustment step, the refrigerant amount supplied to each indoor unit is adjusted by the sub-electronic expansion valve provided between each indoor unit and each electronic expansion valve.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated inFIG. 1, an air conditioner according to the present invention comprises an outdoor unit and a plurality of indoor units.

As illustrated inFIG. 1andFIG. 2, a multi-air conditioner according to the present invention comprises an outdoor unit40installed outside and a plurality of indoor units. The plurality of the indoor units comprises an indoor unit10in Room A, an indoor unit20in Room B and an indoor unit30in Room C.

The outdoor unit40comprises a compressor41compressing a refrigerant in the gaseous state of high temperature and high pressure, a 4-way valve42converting flow of the gaseous state refrigerant emitted from the compressor41according to operation condition such as cooling/heating, an outdoor heat exchanger43condensing the gas refrigerant compressed in the compressor41into a liquid state refrigerant of low temperature and high pressure, and an outdoor pan44sending the air inhaled from outside to the outdoor heat exchanger43in order to exchange heat without difficulty.

The outdoor unit further comprises an electronic expansion valve45which controls gas temperature emitted from the outdoor heat exchanger43to adjust overheating in heating operation and overcooling in cooling operation, and sub-electronic expansions11,21,31which adjust the refrigerant flow amount based on the condition of the indoor units10,20,30, therein supplying appropriate refrigerant flow amount to each indoor unit.

The indoor units10,20,30comprise indoor heat exchangers12,22,32and indoor pans13,23,33circulating inner air to exchange air in the indoor heat exchangers12,22,32without difficulty.

Reference will now be made in detail to the operation process of the present invention, examples of which are illustrated in the accompanying drawings.

FIG. 1is a configuration view illustrating a refrigerant cycle of a multi-air conditioner according to the present invention and while solid line arrows illustrate refrigerant flow in cooling operation, broken line arrows illustrate refrigerant flow in heating operation.

When the multi-air conditioner according to the present invention operates cooling/heating, the refrigerant compressed in high temperature in the compressor41flows into the outdoor heat exchanger43. Thus the refrigerant is exchanged with outside air and condensed according to spinning of the outdoor pan44.

The refrigerant is lead to the sub-electronic expansions11,21,31of the indoor units10,20,30after passing through the electronic expansion valve45. The refrigerant is expanded in the sub-electronic expansion valves11,21,31and becomes a low temperature refrigerant.

The refrigerant flows into the indoor heat exchangers12,22,32and is exchanged for inside air by the indoor pans13,23,33. When the indoor heat exchanger exchanges the inner air for the refrigerant, the inside air becomes a low temperature air and is emitted into inner space.

Thereafter, the above refrigerant flows into the outdoor unit and flows again into the compressor41. With the repetitive process above described the low-temperature air is supplied to the inner space, thereby cooling the inner space.

The electronic expansion valve45is employed to adjust overheating based on the operation condition of each indoor unit10,20,30. The sub-electronic expansion valves11,21,31of Room A, Room B, and Room C are employed to supply a refrigerant to the indoor units operated and to adjust the amount of the refrigerant flow.

As illustrated inFIG. 2, a control part of Room A15, a control part of Room B25, and a control part of Room C35provided in each indoor unit10,20,30exchange each control signal with an outdoor unit control part46provided in the outdoor unit40, thereby the above operation control performed.

According to the indoor unit control method of the multi-air conditioner above mentioned, it is accomplished by the following control method of the indoor unit to supply appropriate refrigerant amount according to the operation condition of each indoor unit.

As illustrated inFIG. 3, a control method of a multi-air conditioner indoor unit according to the first embodiment of the present invention comprises a share step S110in which the plurality of the indoor units shares and stores operation information among the indoor units; a confirmation step in which each indoor unit confirms that operation information is received by other indoor units; a comparison and judgment step S120in which each indoor unit compares and judges its operation status based on the operation information exchanged among the indoor units; an adjustment step S130in which the amount of refrigerant flow supplied to each indoor unit is adjusted, according to the operation status compared and judged by the each indoor unit.

The share step S110comprises an exchange and storage step in which each indoor unit calculates, exchanges and stores performance ratio by its inlet air temperature value, outlet temperature value and air amount value; and a send/receive step in which each indoor unit sends/receives each performance ratio. The performance ratio is the present outlet performance ratio for regular capability of the indoor unit.

A confirmation step S120is further comprised in which each above indoor unit confirms that each indoor unit receives operation information from the other indoor units. Each indoor unit confirms that every connected indoor unit sends each performance ratio to the other indoor units.

The comparison and judgment step S120in which the each indoor unit compares and judges operation status of every connected indoor unit distinguishes the indoor units which have less than 1 performance ratio and indoor units which have more than 1 performance ratio from the indoor units.

In the comparison and judgment step S130, it is preferred but not necessary that the adjustment step be performed when there are at least one indoor unit with less than 1 performance ratio and at least one indoor unit with more than 1 performance ratio.

In the adjustment step S140, the indoor unit with more than 1 performance ratio adjusts the sub-electronic expansion valve to decrease refrigerant amount and the indoor unit with less than 1 performance ratio adjusts the sub-electronic valve to increase refrigerant amount, resulting in supply appropriate refrigerant amount to each indoor unit.

A control method of the multi-air conditioner according to the second embodiment of the present invention referring toFIG. 4aandFIG. 4bis the following.

As illustrated inFIG. 4aandFIG. 4b, a multi-air conditioner according to the second embodiment of the present invention also comprises a share step, a confirmation step, a comparison and judgment step, and an adjustment step.

However, the multi-air conditioner according to the second embodiment of the invention has different operation information which is sent/received and shared among the indoor units, so that the control method of the indoor unit comparing and judging operation status of the indoor units is different from the control method according to the first embodiment.

That is, according to the second embodiment different from the first embodiment, in the share step S210each indoor unit sends/receives and stores each outlet air temperature value alone.

In the confirmation step S220, each indoor unit confirms that every connected indoor unit receives its outlet air temperature value.

The comparison and judgment step S230comprises a calculation step S321in which each indoor unit collects the outlet air temperature value of the indoor unit and calculates average outlet air temperature value and a comparison step S323which distinguishes indoor units with lower outlet air temperature value or higher outlet air temperature value than average outlet temperature value among indoor units comparing the average outlet air temperature value with the outlet air temperature value of the each indoor unit.

In the comparison and judgment step S230, the adjustment step S240may be performed in case that there are at least one indoor unit which has lower outlet air temperature value than average outlet air temperature value, and at least one indoor unit which has higher outlet air temperature value than average outlet air temperature value.

After the performance of the comparison and judgment step of the outlet air temperature vale, the adjustment step S240adjusts the sub-electronic expansion valve connected to the indoor unit to decrease the refrigerant amount supplied to the indoor unit which has lower outlet air temperature value than average outlet air temperature value when the multi-air conditioner performs cooling as illustrated inFIG. 4a.

The adjustment step S240adjusts the sub-electronic expansion valve connected to the indoor unit to decrease the refrigerant amount supplied to the indoor unit which has higher outlet air temperature value than average outlet air temperature value when the multi-air conditioner performs heating as illustrated inFIG. 4b.

A control method of the multi-air conditioner according to the third embodiment of the present invention referring toFIG. 5aandFIG. 5bis the following.

As illustrated inFIG. 5aandFIG. 5b, a multi-air conditioner according to the third embodiment of the present invention also comprises a share step, a confirmation step, a comparison and judgment step, and an adjustment step.

However, the multi-air conditioner according to the second embodiment of the invention has different operation information which is sent/received and shared among the indoor units, so that the control method of the indoor unit comparing and judging operation status of the indoor units is different from the control method according to the first embodiment.

That is, according to the third embodiment different from the first embodiment, in the share step S310each indoor unit sends/receives and stores each pipe temperature value alone.

In the confirmation step S320, each indoor unit confirms that every connected indoor unit receives its pipe temperature value.

The comparison and judgment step S330comprises a calculation step S331in which each indoor unit collects pipe temperature value of the indoor units and calculates average pipe temperature value and a comparison step S332which distinguishes the indoor unit with lower pipe temperature value or higher pipe temperature value than average pipe temperature value among indoor units comparing the average pipe temperature value with the pipe temperature value of the each indoor unit.

In the comparison and judgment step S330, the adjustment step S340may be performed in case that there are at least one indoor unit which has lower pipe temperature value than average pipe temperature value, and at least one indoor unit which has higher pipe temperature value than average pipe temperature value.

After the performance of the comparison and judgment step of the pipe temperature vale, the adjustment step S340adjusts the sub-electronic expansion valve connected to the indoor unit to decrease the refrigerant amount supplied to the indoor unit which has lower pipe temperature value than average pipe temperature value when the multi-air conditioner performs cooling as illustrated inFIG. 5a.

The adjustment step S340adjusts the sub-electronic expansion valve connected to the indoor unit to decrease the refrigerant amount supplied to the indoor unit which has higher pipe temperature value than average pipe temperature value when the multi-air conditioner performs heating as illustrated inFIG. 5b.

In the embodiments of the invention, performance ratio, outlet air temperature value and pipe temperature value are suggested as examples of operation information sent/received and shared among indoor units. Each indoor unit may be controlled by other capability variables such as inlet air temperature value.

As described above, the present invention may adjust the refrigerant amount according to the operation status of each indoor unit and prevent the unbalance of the refrigerant flow amount and the capability variation which may be caused by that a plurality of indoor units is connected to one outdoor unit, therein enhancing cooling/heating efficiency of multi-air conditioners.