Climate control system minimum compressor speed based on refrigerant line diameter

Abstract

A controller for a climate control system that is operatively coupled to a compressor and that includes control circuitry. The control circuitry is configured to receive a diameter of at least one of the one or more refrigerant lines, and adjust a minimum operating speed of the compressor based at least in part on the diameter to provide a minimum flow velocity for the refrigerant to return oil to the compressor through the fluid circuit during operation of the climate control system.

What is claimed is: 
     
         1 . A climate control system comprising:
 an evaporator;   a condenser;   one or more refrigerant lines that partially define a fluid circuit for a refrigerant between the evaporator and the condenser;   a variable speed compressor lubricated by oil, the compressor being coupled to the fluid circuit so that the oil is exposed to the refrigerant; and   a controller operatively coupled to the compressor and including control circuitry that is configured to:
 receive a diameter of at least one of the one or more refrigerant lines; and 
 adjust a minimum operating speed of the compressor based at least in part on the diameter to provide a minimum flow velocity for the refrigerant to return oil to the compressor through the fluid circuit during operation of the climate control system. 
   
     
     
         2 . The climate control system of  claim 1 , wherein the control circuitry is configured to:
 select a plurality of compressor speed maps based at least in part on the refrigerant line diameter;   select a first compressor speed map of the plurality of compressor speed maps based an operating mode of the climate control system, wherein the first compressor speed map defines the minimum operating speed; and   adjust the operating speed of the compressor within the first compressor speed map.   
     
     
         3 . The climate control system of  claim 2 , further comprising a temperature sensor that is configured to detect a value indicative of an outdoor ambient temperature, wherein the control circuitry is configured to adjust the operating speed within the first compressor speed map based at least in part on the outdoor ambient temperature. 
     
     
         4 . The climate control system of  claim 2 , wherein the operating mode comprises a cooling mode or a heating mode. 
     
     
         5 . The climate control system of  claim 2 , wherein the control circuitry is configured to receive the diameter as a user input and to apply a default diameter in an absence of the user input. 
     
     
         6 . The climate control system of  claim 5 , wherein the default diameter is a maximum diameter of the one or more refrigerant lines. 
     
     
         7 . A method of controlling an operating speed of a compressor of a climate control system, the method comprising:
 (a) receiving a diameter of a refrigerant line of the climate control system with a control circuitry;   (b) selecting, via the control circuitry, a compressor speed map for the compressor based at least in part on a type of refrigerant of the climate control system and the diameter of the refrigerant line, the compressor speed map defining a minimum operating speed of the compressor to return oil to the compressor via the refrigerant line; and   (c) preventing operation of the compressor below the minimum operating speed via the control circuitry.   
     
     
         8 . The method of  claim 7 , wherein (c) further comprises:
 (c1) selecting, the compressor speed map from a plurality of compressor speed maps based at least in part on the diameter of the refrigerant line.   
     
     
         9 . The method of  claim 8 , wherein (c1) further comprises selecting, via the control circuitry, the compressor speed map based also on an operating mode of the climate control system. 
     
     
         10 . The method of  claim 9 , wherein the operating mode comprises a cooling mode or a heating mode. 
     
     
         11 . The method of  claim 9 , further comprising:
 (e) determining an outdoor ambient temperature; and   wherein (d) further comprises adjusting the operating speed of the compressor within the compressor speed map based at least in part on the outdoor ambient temperature.   
     
     
         12 . The method of  claim 7 , wherein the control circuitry is at least partially included with a system controller that is configured as a thermostat for the climate control system. 
     
     
         13 . A climate control system, comprising:
 a first unit including a first heat exchanger;   a second unit including a second heat exchanger and a variable speed or variable capacity compressor;   a refrigerant line coupled between the first unit and the second unit; and   control circuitry communicatively coupled to the compressor, the control circuitry configured to:
 receive a diameter of the refrigerant line; and 
 select a compressor speed map for the compressor based at least in part on a type of refrigerant of the climate control system and the diameter of the refrigerant line, the compressor speed map defining a minimum operating speed of the compressor. 
   
     
     
         14 . The climate control system of  claim 13 , wherein the control circuitry is configured to select the compressor speed map from a plurality of compressor speed maps. 
     
     
         15 . The climate control system of  claim 14 , wherein the control circuitry is further configured to select the compressor speed map based on an operating mode of the climate control system. 
     
     
         16 . The climate control system of  claim 15 , wherein the operating mode comprises a cooling mode or a heating mode. 
     
     
         17 . The climate control system of  claim 15 , further comprising a temperature sensor that is configured to detect a value indicate of an outdoor ambient temperature and produce an output, and
 wherein the control circuitry is further configured to:
 receive the output from the temperature sensor; and 
 adjust the operating speed of the compressor within the compressor speed map based at least in part on the output from the temperature sensor. 
   
     
     
         18 . The climate control system of  claim 13 , further comprising a controller that is co-located with the compressor, wherein the controller at least partially includes control circuitry. 
     
     
         19 . The climate control system of  claim 13 , wherein the control circuitry is configured to receive the diameter of the refrigerant line as a user input. 
     
     
         20 . The climate control system of  claim 19 , wherein the control circuitry is configured to apply a default refrigerant line diameter in an absence of the user input.