Compressor protection for refrigerant systems

Abstract

A method and a system for controlling a refrigerant system is disclosed. A method includes monitoring a plurality of refrigerant system parameters using a plurality of sensors. A first warning is generated by one of the plurality of sensors in response to a first parameter exceeding a first threshold. If the first parameter exceeds a second threshold, or all of the plurality of sensors generate warnings, a control system shuts down compressors of the refrigerant system for at least a first predetermined time period. The control system further causes operation of a plurality of fans for at least a second time period, wherein the second period may be greater than, less than, or equal to the first time period. The method also includes incrementing a variable value usable to determine a time at which normal operation of the refrigerant system is to resume.

What is claimed is: 
     
         1 . A method for controlling a refrigerant system, the method comprising:
 monitoring, using a plurality of sensors of the refrigerant system, a plurality of refrigerant system parameters;   generating, using at least one of the plurality of sensors, a first warning in response to a first parameter of the plurality of refrigerant system parameters meeting or exceeding a first threshold; and   using a control system, and in response to the first parameter meeting or exceeding a second threshold greater than the first threshold:
 shutting down a plurality of compressors of the refrigerant system for at least a first predetermined time period; 
 operating a plurality of fans of the refrigerant system for at least a second predetermined time period; and 
 incrementing, using the control system, a variable value usable to determine a time at which normal operation of the refrigerant system is to resume. 
   
     
     
         2 . The method of  claim 1 , further comprising:
 determining, using the control system and after a third predetermined time period, that the first parameter is less than a third threshold, wherein the third threshold is less than the first threshold;   comparing, using the control system, the variable value to a fourth threshold;   resuming normal operation in response to determining that the variable value is less than the fourth threshold; and   performing a lockout to inhibit resumption of normal operation if the variable value is not less than the fourth threshold.   
     
     
         3 . The method of  claim 2 , wherein the fourth threshold is a user input value. 
     
     
         4 . The method of  claim 1 , further comprising resetting the variable value to a start value in response to the refrigerant system operating for at least a third predetermined time period. 
     
     
         5 . The method of  claim 1 , further comprising resetting the variable value to a start value in response to a restart of the control system. 
     
     
         6 . The method of  claim 1 , wherein the plurality of refrigerant system parameters includes at least one pressure reading in the refrigerant system. 
     
     
         7 . The method of  claim 1 , wherein the plurality of refrigerant system parameters includes at least one lower flammability limit. 
     
     
         8 . The method of  claim 1 , further comprising closing a safety shutoff valve in response to the first parameter exceeding a second threshold greater than the first threshold. 
     
     
         9 . The method of  claim 1 , further comprising closing a safety shutoff valve in response to each of the plurality of sensors reporting respective warnings. 
     
     
         10 . The method of  claim 1 , further comprising performing the shutting down, the operating, and the incrementing in response to each of the plurality of sensors reporting respective warnings. 
     
     
         11 . A system for controlling parameters of a refrigerant system, the system comprising:
 a plurality of sensors configured to sense at least a first parameter of a plurality of parameters of the refrigerant system, wherein each of the plurality of sensors is configured to generate a first warning if a first parameter meets or exceeds a first threshold; and   a controller, wherein the controller is configured to:
 shut down a plurality of compressors for at least a first predetermined time period in response to the first parameter meeting or exceeding a second threshold or the plurality of sensors generating respective warnings; 
 operate a plurality of fans of the refrigerant system for at least a second predetermined time period; and 
 increment a first variable usable to determine a time at which normal operation of the refrigerant system is to resume. 
   
     
     
         12 . The system of  claim 11 , wherein the controller is further configured to:
 determine, after a third predetermined time period, that the first parameter is less than a third threshold, wherein the third threshold is less than the first threshold;   compare the first variable to a fourth threshold;   resume normal operation in response to determining that the first variable is less than the fourth threshold; and   perform a lockout to inhibit resumption of normal operation if the first variable is not less than the fourth threshold, wherein the fourth threshold is a user input value.   
     
     
         13 . The system of  claim 11 , wherein the controller is further configured to reset the first variable to a start value in response to the refrigerant system operating for at least a third predetermined time period. 
     
     
         14 . The system of  claim 11 , wherein the controller is further configured to reset the first variable to a start value in response to a restart of the control system. 
     
     
         15 . The system of  claim 11 , wherein the plurality of refrigerant system parameters includes one or more of the following:
 at least one pressure reading in the refrigerant system; and   at least one lower flammability limit.   
     
     
         16 . The system of  claim 11 , further comprising a safety shutoff valve configured to close in response to one or more of the following:
 the first parameter exceeding the second threshold; and   each of the plurality of sensors reporting respective warnings.   
     
     
         17 . The system of  claim 11 , wherein the controller is further configured to perform the shutting down of the plurality of compressors, the operating of the plurality of fans, and the incrementing of the first variable in response to each of the plurality of sensors reporting respective warnings. 
     
     
         18 . A refrigerant system comprising:
 one or more compressors configured to compress a refrigerant and further configured to circulate the refrigerant;   an evaporator coil coupled to the one or more compressors, the evaporator coil configured to receive low-pressure refrigerant and further configured to facilitate heat absorption from an environment to vaporize the refrigerant;   a condenser coil coupled to the one or more compressors and the evaporator coil, the condenser coil configured to receive high-pressure vaporized refrigerant from the one or more compressors and facilitate heat dissipation to condense the refrigerant into a liquid state; and   a monitoring system configured to monitor for leaks in piping connecting the one or more compressors, the evaporator coil, and the condenser coil, wherein the monitoring system comprises:
 a plurality of sensors configured to sense one or more of a plurality of parameters of the refrigerant system, wherein each of the plurality of sensors is configured to generate a first warning if a given one of the plurality of parameters meets or exceeds a first threshold; and 
 a control system configured to: 
 shut down the one or more compressors for at least a first predetermined time period in response to the given one of the plurality of parameters meeting or exceeding a second threshold or the plurality of sensors generating respective warnings; 
 operate a plurality of fans of the refrigerant system for at least a second predetermined time period; and 
 increment a first variable usable to determine a time at which normal operation of the refrigerant system is to resume. 
   
     
     
         19 . The refrigerant system of  claim 18 , wherein the control system is further configured to:
 determine, after a third predetermined time period, that the given one of the plurality of parameters is less than a third threshold, wherein the third threshold is less than the first threshold;   compare the first variable to a fourth threshold;   resume normal operation in response to determining that the first variable is less than the fourth threshold; and   perform a lockout to inhibit resumption of normal operation if the first variable is not less than the fourth threshold, wherein the fourth threshold is a user input value.   
     
     
         20 . The refrigerant system of  claim 18 , wherein the control system is further configured to perform the shutting down of the one or more compressors, the operating of the plurality of fans, and the incrementing of the first variable in response to each of the plurality of sensors reporting respective warnings.