Variable capacity air conditioning system

Abstract

A direct current (DC) powered variable capacity air conditioning system is provided. The system includes a plurality of temperature sensors for monitoring the temperature of various components, locations and air flows within the system. The system additionally includes an integrated controller board that substantially simultaneously controls a variable speed DC compressor motor, a variable speed condenser air mover and a variable speed evaporator air mover in response to inputs from the sensors. By substantially simultaneously controlling the variable speed DC compressor motor, the variable speed condenser air mover and the variable speed evaporator air mover, the system substantially simultaneously controls at least one of a temperature and a volume of an evaporator output air flow. Thus, the system provides a continuum of evaporator output air flow temperatures and capacities for maintaining an approximately constant temperature within an enclosed environment.

1 . A direct current (DC) powered variable capacity air conditioning system, said system comprising an integrated controller board configured to substantially simultaneously control a variable speed DC compressor motor, a variable speed condenser air mover and a variable speed evaporator air mover in response to inputs from a plurality of temperature sensors within the system to substantially simultaneously control at least one of a temperature and a volume of an evaporator output air flow of the system.  
   
   
       2 . The system of  claim 1 , wherein the integrated controller board comprises a compressor motor controller, a condenser air mover controller and an evaporator air mover controller that are controlled by a processor of the integrated controller board.  
   
   
       3 . The system of  claim 1 , wherein the integrated controller board is configured to execute an operation control algorithm to substantially simultaneously control the variable speed DC compressor motor, the variable speed condenser air mover and the variable speed evaporator air mover.  
   
   
       4 . The system of  claim 1 , wherein at least one of the variable speed condenser air mover and the variable speed evaporator air mover comprises a backward-curved impeller.  
   
   
       5 . The system of  claim 1 , wherein the system integrated controller board is located within a path of an evaporator air flow.  
   
   
       6 . The system of  claim 1 , wherein the variable speed DC compressor motor comprises a variable speed brushless DC motor.  
   
   
       7 . The system of  claim 6 , wherein the variable speed brushless DC motor comprises a sensorless variable speed brushless DC motor.  
   
   
       8 . The system of  claim 1 , wherein the system further comprises at least one relative humidity sensor located within an enclosed environment to be air conditioned by the system.  
   
   
       9 . The system of  claim 1 , wherein the plurality of temperature sensors comprise an evaporator intake air flow sensor, an evaporator refrigerant inlet sensor, an evaporator refrigerant outlet sensor, condenser refrigerant outlet sensor and a condenser intake air flow sensor.  
   
   
       10 . The system of  claim 9 , wherein the plurality of temperature sensors further comprise at least one of a compressor housing sensor, a controller board heat sink sensor, and at least one remote sensor located within an enclosed environment to be air conditioned by the system.  
   
   
       11 . The system of  claim 1 , wherein the system further comprises at least one variable output positive temperature coefficient heater controlled by the controller board substantially simultaneously with the variable speed evaporator air mover.  
   
   
       12 . The system of  claim 1 , wherein the system further comprises a charge mode device removably connectable to the integrated controller board for placing the system in a charging mode.  
   
   
       13 . The system of  claim 1 , wherein the system further comprises a stepper-motor type electronically variable expansion valve controlled by the integrated controller board based on a sensed temperature of a system refrigerant exiting an evaporator heat exchanger of the system and a sensed temperature of the system refrigerant entering the evaporator heat exchanger.  
   
   
       14 . A method for controlling a temperature within an enclosed environment, said method comprising substantially simultaneously controlling at least one of a temperature and a volume of an evaporator output air flow of a direct current (DC) powered variable capacity air conditioning system utilizing an integrated controller board that uses a plurality of temperature inputs from a plurality of sensors within the system to substantially simultaneously control a variable speed DC compressor motor, a variable speed condenser air mover and a variable speed evaporator air mover, thereby providing a continuum of evaporator output air flow capacities for maintaining an approximately constant temperature within the enclosed environment.  
   
   
       15 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and volume of the evaporator output air flow comprises varying at least one of the temperature and the volume of the an evaporator output air flow in response to the sensor inputs.  
   
   
       16 . The method of  claim 14 , wherein monitoring inputs comprises receiving as inputs to the integrated controller board, temperature readings of an evaporator intake air flow, an evaporator refrigerant inlet, an evaporator refrigerant outlet, a condenser refrigerant outlet, a condenser intake air flow, a controller board heat sink, a compressor housing and at least one remote location within an enclosed environment to be air conditioned by the air conditioning system.  
   
   
       17 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises controlling operation of at least one of the variable speed DC compressor motor, the variable speed condenser air mover and the variable speed evaporator air mover when a temperature within the enclosed environment is outside of a desired temperature set point range.  
   
   
       18 . The method of  claim 17 , wherein the set point range is programmable to temporally vary.  
   
   
       19 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises controlling operation of the variable speed DC compressor motor, the variable speed evaporator air mover and at least one variable output positive temperature coefficient heater based on the sensor inputs.  
   
   
       20 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises: 
 determining a superheat state of a system refrigerant at an evaporator refrigerant outlet based on a temperature difference between an evaporator refrigerant inlet and an evaporator refrigerant inlet; and    controlling the superheat state by controlling operation of at least one of the variable speed evaporator air mover and a thermal expansion valve of the air conditioning system.    
   
   
       21 . The method of  claim 20 , wherein the thermal expansion valve comprises a stepper-motor type electronically variable expansion valve and controlling the operation the thermal expansion valve comprises utilizing the integrated controller board to control the stepper-motor type electronically variable expansion valve based on a sensed temperature of the system refrigerant exiting an evaporator heat exchanger of the air conditioning system and a sensed temperature of the system refrigerant entering the evaporator heat exchanger.  
   
   
       22 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises controlling operation of the variable speed condenser fan to produce a desired float temperature based on a temperature difference between a condenser intake air flow and a temperature of a condenser refrigerant outlet.  
   
   
       23 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the of the evaporator output air flow comprises: 
 updating a state estimate of a compressor rotor based on a temperature difference between an evaporator refrigerant inlet and a condenser refrigerant outlet; and    controlling operation of the variable speed DC compressor motor based on the updated state estimate.    
   
   
       24 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises: 
 monitoring a condenser intake air flow temperature to determine environmental conditions exterior to the air conditioning unit that may be detrimental to the air conditioning system; and    shutting down the air conditioning system if the exterior environmental conditions are determined to be detrimental.    
   
   
       25 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises controlling operation of the variable speed condenser air mover based on a compressor housing temperature to prevent the compressor from overheating.  
   
   
       26 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises: 
 monitoring a temperature of a heat sink of the integrated controller board to determine; and    controlling operation of at least one of the variable speed evaporator air mover and the variable speed DC compressor motor, based on the heat sink temperature to prevent a power electronics portion of the integrated controller board from overheating.    
   
   
       27 . The method of  claim 14 , wherein substantially simultaneously controlling at least one of the temperature and the volume of the evaporator output air flow comprises executing an operation control algorithm, via a processor of the integrated controller board, to substantially simultaneously control the variable speed DC compressor motor, the variable speed condenser air mover and the variable speed evaporator air mover.  
   
   
       28 . The method of  claim 14 , wherein the method further comprises executing a self-test mode algorithm, via a processor of the integrated controller board, to test functionality of the variable capacity air conditioning system.  
   
   
       29 . A telecommunications station comprising: 
 a direct current (DC) powered variable capacity air conditioning system coupled to a structure enclosing an environment to be thermally conditioned by the DC powered variable capacity air conditioning system, said system comprising: 
 a plurality of temperature sensors;  
 a variable speed DC compressor motor;  
 a variable speed condenser air mover;  
 a variable speed evaporator air mover; and  
 an integrated controller board configured to substantially simultaneously control the variable speed DC compressor motor, the variable speed condenser air mover and the variable speed evaporator air mover in response to inputs from the temperature sensors to substantially simultaneously control at least one of a temperature and a volume of an evaporator output air flow of the system to the enclosed environment.  
   
   
   
       30 . The station of  claim 29 , wherein the integrated controller board is configured to execute an operation control algorithm to substantially simultaneously control a compressor motor controller, a condenser air mover controller and an evaporator air mover controller to substantially simultaneously control the variable speed DC compressor motor, the variable speed condenser air mover and the variable speed evaporator air mover.  
   
   
       31 . The station of  claim 29 , wherein the variable speed DC compressor motor comprises a sensorless variable speed brushless DC motor.  
   
   
       32 . The station of  claim 29 , wherein the plurality of temperature sensors comprise an evaporator intake air flow sensor, an evaporator refrigerant inlet sensor, an evaporator refrigerant outlet sensor, condenser refrigerant outlet sensor and a condenser intake air flow sensor.  
   
   
       33 . The station of  claim 29 , wherein the system further comprises at least one variable output positive temperature coefficient heater controlled by the controller board substantially simultaneously with the variable speed evaporator air mover.  
   
   
       34 . The station of  claim 29 , wherein the system further comprises a charge mode device removably connectable to the integrated controller board for placing the system in a charging mode.  
   
   
       35 . A direct current (DC) powered variable capacity air conditioning system, said system comprising: 
 a variable speed DC compressor; and    a controller board configured to operate the variable speed DC compressor at varying speeds during operation of the variable capacity air conditioning system.    
   
   
       36 . The system of  claim 35 , wherein the variable speed DC compressor comprises a sensorless variable speed brushless DC motor.