Airflow driving device having function of measuring flow rate and air conditioner with same

Abstract

An airflow driving device includes an airflow-guiding member for receiving and guiding an airflow. The airflow-guiding member includes a first opening and a second opening. The open areas of the first opening and the second opening are different such that a pressure difference is generated between the first opening and the second opening. According to the pressure difference, a flow rate of the airflow passing through the airflow driving device is calculated.

1 . An airflow driving device of an air conditioner, said airflow driving device comprising:
 an airflow-guiding member for receiving and guiding an airflow, wherein said airflow-guiding member comprises a first opening and a second opening, the open areas of said first opening and said second opening are different such that a pressure difference is generated between said first opening and said second opening, and a flow rate of said airflow passing through said airflow driving device is calculated according to said pressure difference.   
     
     
         2 . The airflow driving device according to  claim 1 , wherein said airflow driving device is a centrifugal fan. 
     
     
         3 . The airflow driving device according to  claim 1 , wherein the open area of said first opening is greater than the open area of said second opening so that the pressure at said first opening is lower than the pressure at said second opening. 
     
     
         4 . The airflow driving device according to  claim 1 , wherein said airflow driving device further comprises an impeller, which is arranged beside said airflow-guiding member and comprises a guiding channel and plural lateral channels, wherein said guiding channel is aligned with said second opening of said airflow-guiding member for receiving said airflow, and said lateral channels are disposed in a periphery of said impeller so that said airflow coming from said guiding channel is exhausted out of said impeller through said lateral channels. 
     
     
         5 . The airflow driving device according to  claim 4 , wherein said airflow driving device further comprises a volute, which comprises a receptacle, a third opening, an airflow path and a fourth opening, wherein said fourth opening is arranged at a first side of said volute and in communication with said receptacle, said impeller is inserted into said receptacle of said volute through said fourth opening, and said third opening is in communication with said receptacle and said airflow path so that said airflow coming from said lateral channels is introduced into said airflow path through said third opening. 
     
     
         6 . The airflow driving device according to  claim 1 , wherein said air conditioner further comprises a first pressure-detecting device, a second pressure-detecting device and a controlling circuit, wherein a first pressure at said first opening is detected by said first pressure-detecting device, a second pressure at said second opening is detected by said second pressure-detecting device, and said controlling circuit calculates said flow rate of said second airflow passing through said airflow driving device according to said first pressure and said second pressure. 
     
     
         7 . An air conditioner, comprising:
 a casing;   a heat exchanger disposed within said casing for transferring heat of a first airflow and producing a second airflow;   an airflow driving device for guiding said second airflow to be exhausted out of said air conditioner, wherein said airflow driving device comprises an airflow-guiding member with a first opening and a second opening, wherein the open areas of said first opening and said second opening are different;   a first pressure-detecting device for detecting a first pressure at said first opening;   a second pressure-detecting device for detecting a second pressure at said second opening; and   a controlling circuit for calculating a flow rate of said second airflow passing through said airflow driving device according to said first pressure and said second pressure.   
     
     
         8 . The air conditioner according to  claim 7 , wherein said casing comprises an inlet and an outlet, wherein said first airflow is introduced into said casing through said inlet, and said second airflow is exhausted out of said casing through said outlet. 
     
     
         9 . The air conditioner according to  claim 7 , wherein a pressure difference is generated between said first opening and said second opening. 
     
     
         10 . The air conditioner according to  claim 9 , wherein said flow rate of said second airflow passing through said airflow driving device is deduced according to the following formula built in said controlling circuit: 
       
         
           
             
               
                 Q 
                 = 
                 
                   Y 
                    
                   
                     
                       
                         Δ 
                          
                         
                             
                         
                          
                         P 
                       
                       ρ 
                     
                   
                    
                   
                     ∑ 
                     CnAn 
                   
                 
               
               , 
             
           
         
         where, Q is said flow rate of said second airflow passing through said airflow driving device, Y is an expansion factor, ΔP is a pressure difference between said first opening and said second opening, ρ is an air density, Cn is a flow rate coefficient at the n th  differential distance from said first opening, and An is an open area at the n th  differential distance from said first opening.