US2014216704A1PendingUtilityA1

Method for operating an hvac system

Assignee: GEN ELECTRICPriority: Feb 7, 2013Filed: Feb 7, 2013Published: Aug 7, 2014
Est. expiryFeb 7, 2033(~6.5 yrs left)· nominal 20-yr term from priority
F24F 11/63F24F 11/46F24F 11/62F24F 11/65F24F 11/30F24F 11/64F28F 27/00
48
PatentIndex Score
0
Cited by
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Claims

Abstract

A method for operating an HVAC system is provided. The method includes providing a model for an indoor temperature, y, of a building, providing predicted future outdoor temperatures, and calculating an activation time or an adjustment time interval for the HVAC system utilizing at least the model for y and the predicted future outdoor temperatures. Operation of the HVAC system can be improved with the activation time or the adjustment time interval.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
         1 . A method for operating an HVAC system, the HVAC system configured for cooling air within a building, heating air within the building, or both, the method comprising:
 providing a model for an indoor temperature, y, of the building;   providing predicted future outdoor temperatures;   calculating an adjustment time interval for the HVAC system utilizing at least the model for y and the predicted future outdoor temperatures.   
     
     
         2 . The method of  claim 1 , wherein the adjustment time interval corresponds to a period of time required for the HVAC system to adjust the indoor temperature of the building from an initial temperature, T 0 , to a final temperature, T f , wherein T 0  and T f  are unequal. 
     
     
         3 . The method of  claim 2 , further comprising:
 determining an initial time, t 0 , at which the indoor temperature of the building is T 0  and a final time, t f , at which the indoor temperature of the building is T f , the adjustment time interval corresponding to the difference between t 0  and t f ; and   activating the HVAC system at t 0  such the indoor temperature of the building is T f  at t f .   
     
     
         4 . The method of  claim 1 , wherein the model for y comprises a second order linear model. 
     
     
         5 . The method of  claim 4 , wherein the model for y comprises
     y   k   =a   1   y   k−1   +a   2   y   k−2   +b   1   v   k−1   +b   2   u   k−1      
       where
 y k  is an indoor temperature of the building at time k, 
 y k−1  is an indoor temperature of the building at time k−1, 
 y k−2  is an indoor temperature of the building at time k−2, 
 v k−1  is an outdoor temperature at time k−1, 
 u k−1  is an operating state of the HVAC system at time k−1, and 
 a 1 , a 2 , b 1 , and b 2  are constants. 
 
     
     
         6 . The method of  claim 1 , wherein said step of calculating comprises calculating the adjustment time interval with the following: 
       
         
           
             
               
                 y 
                 f 
               
               = 
               
                 
                   
                     CA 
                     k 
                   
                    
                   
                     x 
                     
                       k 
                       0 
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       0 
                     
                     
                       N 
                       - 
                       1 
                     
                   
                    
                   
                       
                   
                    
                   
                     
                       CA 
                       
                         N 
                         - 
                         i 
                         - 
                         1 
                       
                     
                      
                     
                       BU 
                       i 
                     
                   
                 
               
             
           
         
         
           
             where 
           
         
         
           
             
               
                 C 
                 = 
                 
                   [ 
                   
                     
                       
                         1 
                       
                       
                         0 
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 A 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           a 
                           1 
                         
                       
                       
                         
                           a 
                           2 
                         
                       
                     
                     
                       
                         1 
                       
                       
                         0 
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 B 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           b 
                           1 
                         
                       
                       
                         
                           b 
                           2 
                         
                       
                     
                     
                       
                         1 
                       
                       
                         0 
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 
                   x 
                   
                     k 
                     0 
                   
                 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           y 
                           
                             k 
                             0 
                           
                         
                       
                     
                     
                       
                         
                           y 
                           
                             
                               k 
                               0 
                             
                             - 
                             1 
                           
                         
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 
                   U 
                   i 
                 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           v 
                           i 
                         
                       
                     
                     
                       
                         
                           u 
                           i 
                         
                       
                     
                   
                   ] 
                 
               
               , 
             
           
         
       
       and
 N=k f −k 0  where k 0  is an initial time at which the indoor temperature of the building is an initial temperature, y k     0   , and k f  is a final time at which the indoor temperature of the building is a final temperature, y k     f   . 
 
     
     
         7 . The method of  claim 1 , wherein said step of calculating comprises calculating the adjustment time interval in order to minimize energy consumption of the HVAC system. 
     
     
         8 . The method of  claim 7 , wherein said step of calculating comprises calculating the adjustment time interval with the following: 
       
         
           
             
               T 
               ← 
               
                 
                   
                     CA 
                     N 
                   
                    
                   
                     x 
                     
                       k 
                       0 
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       0 
                     
                     
                       N 
                       - 
                       1 
                     
                   
                    
                   
                       
                   
                    
                   
                     
                       
                         ( 
                         
                           
                             CA 
                             
                               N 
                               - 
                               i 
                               - 
                               1 
                             
                           
                            
                           B 
                         
                         ) 
                       
                       1 
                     
                      
                     
                       v 
                       i 
                     
                   
                 
               
             
           
         
         
           
             
               
                 k 
                 * 
               
               ← 
               
                 
                   k 
                   f 
                 
                 - 
                 1 
               
             
           
         
         
           
             
               
                 while 
                  
                 
                     
                 
                  
                 T 
               
               < 
               
                 
                   T 
                   f 
                 
                  
                 
                     
                 
                  
                 do 
               
             
           
         
         
           
             
               T 
               ← 
               
                 T 
                 + 
                 
                   
                     ( 
                     
                       
                         CA 
                         
                           
                             k 
                             f 
                           
                           - 
                           
                             k 
                             * 
                           
                         
                       
                        
                       B 
                     
                     ) 
                   
                   2 
                 
               
             
           
         
         
           
             
               
                 k 
                 * 
               
               ← 
               
                 
                   k 
                   * 
                 
                 - 
                 1 
               
             
           
         
         
           
             
               end 
                
               
                   
               
                
               while 
             
           
         
       
       where
 T is the indoor temperature of the building and 
 k* is a time value. 
 
     
     
         9 . The method of  claim 1 , wherein said step of providing predicted future outdoor temperatures comprises determining predicted future outdoor temperatures based upon weather forecast data. 
     
     
         10 . The method of  claim 9 , wherein said step of providing predicted future outdoor temperatures comprises providing predicted future outdoor temperatures using the following: 
       
         
           
             
               
                 f 
                  
                 
                   ( 
                   t 
                   ) 
                 
               
               = 
               
                 { 
                 
                   
                     
                       
                         
                           
                             
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   + 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                               - 
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   - 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                             
                           
                         
                         
                           
                             
                               cos 
                                
                               
                                 ( 
                                 
                                   
                                     π 
                                      
                                     
                                       ( 
                                       
                                         t 
                                         - 
                                         
                                           
                                             t 
                                             min 
                                           
                                            
                                           
                                             ( 
                                             k 
                                             ) 
                                           
                                         
                                       
                                       ) 
                                     
                                   
                                   
                                     
                                       
                                         t 
                                         max 
                                       
                                        
                                       
                                         ( 
                                         k 
                                         ) 
                                       
                                     
                                     - 
                                     
                                       
                                         t 
                                         min 
                                       
                                        
                                       
                                         ( 
                                         k 
                                         ) 
                                       
                                     
                                   
                                 
                                 ) 
                               
                             
                           
                         
                       
                     
                     
                       
                         t 
                         ∈ 
                         
                           [ 
                           
                             
                               
                                 t 
                                 min 
                               
                                
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                             , 
                             
                               
                                 t 
                                 max 
                               
                                
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                           
                           ) 
                         
                       
                     
                   
                   
                     
                       
                         
                           
                             
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   + 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       
                                         k 
                                         + 
                                         1 
                                       
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                               + 
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   - 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       
                                         k 
                                         + 
                                         1 
                                       
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                             
                           
                         
                         
                           
                             
                               cos 
                                
                               
                                 ( 
                                 
                                   
                                     π 
                                      
                                     
                                       ( 
                                       
                                         t 
                                         - 
                                         
                                           
                                             t 
                                             max 
                                           
                                            
                                           
                                             ( 
                                             k 
                                             ) 
                                           
                                         
                                       
                                       ) 
                                     
                                   
                                   
                                     
                                       
                                         t 
                                         min 
                                       
                                        
                                       
                                         ( 
                                         
                                           k 
                                           + 
                                           1 
                                         
                                         ) 
                                       
                                     
                                     - 
                                     
                                       
                                         t 
                                         max 
                                       
                                        
                                       
                                         ( 
                                         k 
                                         ) 
                                       
                                     
                                   
                                 
                                 ) 
                               
                             
                           
                         
                       
                     
                     
                       
                         t 
                         ∈ 
                         
                           [ 
                           
                             
                               
                                 t 
                                 max 
                               
                                
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                             , 
                             
                               
                                 t 
                                 min 
                               
                                
                               
                                 ( 
                                 
                                   k 
                                   + 
                                   1 
                                 
                                 ) 
                               
                             
                           
                           ) 
                         
                       
                     
                   
                 
               
             
           
         
       
       where
 T max (k) is a maximum temperature on day k, 
 T min (k) is a minimum temperature on day k, 
 t max (k) is a time of day for T max (k), and 
 t min (k) is a time of day for T min (k). 
 
     
     
         11 . A method for operating an HVAC system, the HVAC system configured for cooling air within a building, heating air within the building, or both, the method comprising:
 providing a model for an interior temperature, y, of the building;   providing predicted future exterior temperatures of the building;   calculating an activation time for the HVAC system utilizing at least the model for y and the predicted future outdoor temperatures.   
     
     
         12 . The method of  claim 1 , further comprising:
 turning on the HVAC system at the activation time; and   running the HVAC system in order to adjust the indoor temperature of the building from an initial temperature, T 0 , to a final temperature, T f , after said step of turning on.   
     
     
         13 . The method of  claim 1 , wherein the model for y comprises a second order linear model. 
     
     
         14 . The method of  claim 13 , wherein the model for y comprises
     y   k   =a   1   y   k−1   +a   2   y   k−2   +b   1   v   k−1   +b   2   u   k−1      
       where
 y k  is an indoor temperature of the building at time k, 
 y k−1  is an indoor temperature of the building at time k−1, 
 y k−2  is an indoor temperature of the building at time k−2, 
 v k−1  is an outdoor temperature at time k−1, 
 u k−1  is an operating state of the HVAC system at time k−1, and 
 a 1 , a 2 , b 1 , and b 2  are constants. 
 
     
     
         15 . The method of  claim 1 , wherein said step of calculating comprises calculating the activation time with the following: 
       
         
           
             
               
                 y 
                 f 
               
               = 
               
                 
                   
                     CA 
                     k 
                   
                    
                   
                     x 
                     
                       k 
                       0 
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       0 
                     
                     
                       N 
                       - 
                       1 
                     
                   
                    
                   
                       
                   
                    
                   
                     
                       CA 
                       
                         N 
                         - 
                         i 
                         - 
                         1 
                       
                     
                      
                     
                       BU 
                       i 
                     
                   
                 
               
             
           
         
         
           
             where 
           
         
         
           
             
               
                 C 
                 = 
                 
                   [ 
                   
                     
                       
                         1 
                       
                       
                         0 
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 A 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           a 
                           1 
                         
                       
                       
                         
                           a 
                           2 
                         
                       
                     
                     
                       
                         1 
                       
                       
                         0 
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 B 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           b 
                           1 
                         
                       
                       
                         
                           b 
                           2 
                         
                       
                     
                     
                       
                         1 
                       
                       
                         0 
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 
                   x 
                   
                     k 
                     0 
                   
                 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           y 
                           
                             k 
                             0 
                           
                         
                       
                     
                     
                       
                         
                           y 
                           
                             
                               k 
                               0 
                             
                             - 
                             1 
                           
                         
                       
                     
                   
                   ] 
                 
               
               , 
               
                 
 
               
                
               
                 
                   U 
                   i 
                 
                 = 
                 
                   [ 
                   
                     
                       
                         
                           v 
                           i 
                         
                       
                     
                     
                       
                         
                           u 
                           i 
                         
                       
                     
                   
                   ] 
                 
               
               , 
             
           
         
       
       and
 N=k f −k 0  where k 0  is the activation time at which the indoor temperature of the building is an initial temperature, y k     0   , and k f  is a final time at which the indoor temperature of the building is a final temperature, y k     f   . 
 
     
     
         16 . The method of  claim 1 , wherein said step of calculating comprises calculating the activation time in order to minimize energy consumption of the HVAC system. 
     
     
         17 . The method of  claim 16 , wherein said step of calculating comprises calculating the activation time with the following: 
       
         
           
             
               T 
               ← 
               
                 
                   
                     CA 
                     N 
                   
                    
                   
                     x 
                     
                       k 
                       0 
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       0 
                     
                     
                       N 
                       - 
                       1 
                     
                   
                    
                   
                       
                   
                    
                   
                     
                       
                         ( 
                         
                           
                             CA 
                             
                               N 
                               - 
                               i 
                               - 
                               1 
                             
                           
                            
                           B 
                         
                         ) 
                       
                       1 
                     
                      
                     
                       v 
                       i 
                     
                   
                 
               
             
           
         
         
           
             
               
                 k 
                 * 
               
               ← 
               
                 
                   k 
                   f 
                 
                 - 
                 1 
               
             
           
         
         
           
             
               
                 while 
                  
                 
                     
                 
                  
                 T 
               
               < 
               
                 
                   T 
                   f 
                 
                  
                 
                     
                 
                  
                 do 
               
             
           
         
         
           
             
               T 
               ← 
               
                 T 
                 + 
                 
                   
                     ( 
                     
                       
                         CA 
                         
                           
                             k 
                             f 
                           
                           - 
                           
                             k 
                             * 
                           
                         
                       
                        
                       B 
                     
                     ) 
                   
                   2 
                 
               
             
           
         
         
           
             
               
                 k 
                 * 
               
               ← 
               
                 
                   k 
                   * 
                 
                 - 
                 1 
               
             
           
         
         
           
             
               end 
                
               
                   
               
                
               while 
             
           
         
       
       where
 T is the indoor temperature of the building and 
 k* is the activation time. 
 
     
     
         18 . The method of  claim 1 , wherein said step of providing predicted future outdoor temperatures comprises determining predicted future outdoor temperatures based upon weather forecast data. 
     
     
         19 . The method of  claim 18 , wherein said step of providing predicted future outdoor temperatures comprises providing predicted future outdoor temperatures using the following: 
       
         
           
             
               
                 f 
                  
                 
                   ( 
                   t 
                   ) 
                 
               
               = 
               
                 { 
                 
                   
                     
                       
                         
                           
                             
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   + 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                               - 
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   - 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                             
                           
                         
                         
                           
                             
                               cos 
                                
                               
                                 ( 
                                 
                                   
                                     π 
                                      
                                     
                                       ( 
                                       
                                         t 
                                         - 
                                         
                                           
                                             t 
                                             min 
                                           
                                            
                                           
                                             ( 
                                             k 
                                             ) 
                                           
                                         
                                       
                                       ) 
                                     
                                   
                                   
                                     
                                       
                                         t 
                                         max 
                                       
                                        
                                       
                                         ( 
                                         k 
                                         ) 
                                       
                                     
                                     - 
                                     
                                       
                                         t 
                                         min 
                                       
                                        
                                       
                                         ( 
                                         k 
                                         ) 
                                       
                                     
                                   
                                 
                                 ) 
                               
                             
                           
                         
                       
                     
                     
                       
                         t 
                         ∈ 
                         
                           [ 
                           
                             
                               
                                 t 
                                 min 
                               
                                
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                             , 
                             
                               
                                 t 
                                 max 
                               
                                
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                           
                           ) 
                         
                       
                     
                   
                   
                     
                       
                         
                           
                             
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   + 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       
                                         k 
                                         + 
                                         1 
                                       
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                               + 
                               
                                 
                                   
                                     
                                       T 
                                       max 
                                     
                                      
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                   - 
                                   
                                     
                                       T 
                                       min 
                                     
                                      
                                     
                                       ( 
                                       
                                         k 
                                         + 
                                         1 
                                       
                                       ) 
                                     
                                   
                                 
                                 2 
                               
                             
                           
                         
                         
                           
                             
                               cos 
                                
                               
                                 ( 
                                 
                                   
                                     π 
                                      
                                     
                                       ( 
                                       
                                         t 
                                         - 
                                         
                                           
                                             t 
                                             max 
                                           
                                            
                                           
                                             ( 
                                             k 
                                             ) 
                                           
                                         
                                       
                                       ) 
                                     
                                   
                                   
                                     
                                       
                                         t 
                                         min 
                                       
                                        
                                       
                                         ( 
                                         
                                           k 
                                           + 
                                           1 
                                         
                                         ) 
                                       
                                     
                                     - 
                                     
                                       
                                         t 
                                         max 
                                       
                                        
                                       
                                         ( 
                                         k 
                                         ) 
                                       
                                     
                                   
                                 
                                 ) 
                               
                             
                           
                         
                       
                     
                     
                       
                         t 
                         ∈ 
                         
                           [ 
                           
                             
                               
                                 t 
                                 max 
                               
                                
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                             , 
                             
                               
                                 t 
                                 min 
                               
                                
                               
                                 ( 
                                 
                                   k 
                                   + 
                                   1 
                                 
                                 ) 
                               
                             
                           
                           ) 
                         
                       
                     
                   
                 
               
             
           
         
       
       where
 T max (k) is a maximum temperature on day k, 
 T min (k) is a minimum temperature on day k, 
 t max (k) is a time of day for T max (k), and 
 t min (k) is a time of day for T min (k).

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