Diagnostic Method for Proper Refrigerant Valve Operation

Abstract

There is provided a refrigerant system 100 including at least one or a plurality of refrigerant flow control devices 125 for regulating operational parameters of the refrigerant system 100 , at least one sensor 135, 140 connected to the refrigerant system 100 for monitoring the operational parameters of the refrigerant system 100 , and a controller 130 . The controller 130 , which is connected to the plurality of refrigerant flow control devices 125 and to each of the at least one sensor 135, 140 , switches a refrigerant flow control device 125 of the plurality of refrigerant flow control devices 125 between a first operating state and a second operating state, separately observes a variation in an operational parameter resulting from the switching of each refrigerant flow control device 125 of the plurality of refrigerant flow control devices 125 , compares the observed variation with an expected variation due to the switching, and determines whether the refrigerant flow control device 125 is operating properly based on whether the actual variation corresponds to the expected variation. There is also provided a method for diagnostic testing of the refrigerant system 100.

1 . A method for diagnostic testing of a refrigerant system  100  having at least one refrigerant flow control device  125 , comprising:
 switching said at least one refrigerant flow control device  125  from a first operating state to a second operating state, in response to a diagnostic request from a controller  130 ;   observing a variation in at least one operational parameter of at least a portion of said refrigerant system  100  resulting from said switching of said at least one refrigerant flow control device  125 ; and   comparing said observed variation with an expected variation due to said switching.   
   
   
       2 . The method of  claim 1 , further comprising determining whether said refrigerant flow control device  125  is operating properly based on whether said observed variation corresponds to said expected variation within a predefined tolerance range. 
   
   
       3 . The method of  claim 1 , wherein said refrigerant flow control device  125  is a valve  125 ,
 wherein said first operating state is a first position of said valve  125 , and said first operating state is selected from the group consisting of: completely open, completely closed, and partially closed, and   wherein said second operating state is a second position of said valve  125 , and said second operating state is selected from the group consisting of: completely open, completely closed, and partially closed.   
   
   
       4 . The method of  claim 1 , wherein said operational parameter is selected from a group consisting of temperature, pressure and electric current. 
   
   
       5 . The method of  claim 1 , wherein said system has a plurality of refrigerant flow control devices  125 , and wherein said method is performed individually and sequentially on each of at least two selected refrigerant flow control devices  125  of said plurality of refrigerant flow control devices  125 , and
 wherein during said steps of switching each said refrigerant flow control device  125  and observing said variation, an operating state of untested refrigerant flow control devices  125  of said plurality of refrigerant flow control devices  125 , which have a potential effect on said operational parameter, is unaltered.   
   
   
       6 . The method of  claim 1 , wherein said refrigerant flow control device  125  is determined to be operating properly if said observed variation is substantially equal to said expected variation, and wherein said refrigerant flow control device  125  is determined to be malfunctioning if said observed variation is substantially different from said expected variation. 
   
   
       7 . The method of  claim 1 , wherein said observed variation and said expected variation is selected from the group consisting of:
 a change between a first parameter corresponding to said first operating state and a second parameter corresponding to said second operating state, and   a rate of change in said first parameter.   
   
   
       8 . The method of  claim 1 , further comprising a step selected from the group consisting of:
 returning said at least one refrigerant flow control device  125  to said first operating state after observing said variation, and   allowing said at least one refrigerant flow control device  125  to remain in said second operating state after observing said variation.   
   
   
       9 . The method of  claim 1 , wherein said at least one refrigerant flow control device  125  has more than two operating states, and wherein said method is performed multiple times by switching said at least one refrigerant flow control device  125  to a plurality of operating states, and performing said steps of observing and comparing for each of said plurality of operating states. 
   
   
       10 . The method of  claim 1 , wherein said variation is observed repeatedly over a selected period of time, and changes in said variation are observed to record and analyze degradation of said at least one refrigerant flow control device  125 . 
   
   
       11 . A refrigerant system  100 , comprising:
 at least one refrigerant flow control device  125  for regulating operational parameters of said refrigerant system  100 ;   at least one sensor  135 ,  140  connected to said refrigerant system  100  for monitoring said operational parameters of said refrigerant system  100 ;   a controller  130 , connected to said at least one refrigerant flow control device  125  and to each of said at least one sensor  135 ,  140 , that switches a refrigerant flow control device  125  between a first operating state and a second operating state, observes a variation in at least one operational parameter resulting from said switching of said at least one refrigerant flow control device  125 , and compares said observed variation with an expected variation due to said switching.   
   
   
       12 . The system of  claim 11 , wherein said controller  30  determines whether said refrigerant flow control device  125  is operating properly based on whether said observed variation corresponds to said expected variation within a specified tolerance range. 
   
   
       13 . The system of  claim 11 , wherein said operational parameter is selected from a group consisting of temperature, pressure, and electric current, and wherein said sensor  135 ,  140  is selected from the group consisting of a pressure sensor  135 , a temperature sensor  140 , and an electric current sensor. 
   
   
       14 . The system of  claim 11 , wherein said refrigerant flow control device  125  is a valve  125 , and wherein said first operating state is a first position of said valve  125 , and said second operating state is a second position of said valve  125 . 
   
   
       15 . The system of  claim 11 , further comprising an interface  155  connected to said controller for providing information related to said observed variation and said expected variation, and for receiving input related to said expected variation and from refrigerant flow control devices  125  to be tested. 
   
   
       16 . The system of  claim 11 , wherein said controller  130  determines that said refrigerant flow control device  125  is operating properly if said observed variation is substantially equal to said expected variation, and wherein said controller  130  determines that said refrigerant flow control device  125  is malfunctioning if said observed variation is substantially different from said expected variation. 
   
   
       17 . The system of  claim 11 , wherein said refrigerant system  100  has a plurality of refrigerant flow control devices  125 ,
 wherein said controller is connected to said plurality of refrigerant flow control devices  125 , and   wherein said controller switches at least one refrigerant flow control device  125  of said plurality of refrigerant flow control devices  125  between a first operating state and a second operating state and separately observes a variation in at least one operational parameter resulting from said switching of each said refrigerant flow control device  125 .   
   
   
       18 . The system of  claim 17 , wherein said controller  130  performs at least the switching and separately observing steps individually and sequentially on each of at least two selected refrigerant flow control devices  125  of said plurality of refrigerant flow control devices  125 , and
 wherein during said switching and observing steps, an operating state of untested refrigerant flow control devices  125  of said plurality of refrigerant flow control devices  125 , which have a potential effect on said operational parameter, is unaltered.   
   
   
       19 . The system of  claim 11 , wherein said refrigerant system  100  is selected from the group consisting of a single-circuit system and a multi-circuit system. 
   
   
       20 . A system or method for diagnostic testing of at least one refrigerant flow control device  125  of a plurality of refrigerant flow control devices  125  of a refrigerant system  100  as herein before described with reference to any one of  FIGS. 1 ,  2 ,  3  and  4  of the accompanying drawings.