Systems and Methods for Compressor Design

Abstract

A method for designing a compressor operable to compress a refrigerant. The method may include determining operating conditions for the compressor. The method may also include weighting the operating conditions. The method further include determining a compressor volume ratio based on the refrigerant and the weighted operating conditions.

What is claimed is: 
     
         1 . An HVAC system comprising
 an evaporator;   a condenser;   an expander; and   a single fixed volume ratio compressor operable to compress a refrigerant and having a compressor volume ratio, wherein the compressor volume ratio is determined based on thermodynamic properties of the refrigerant and at least one of:
 the lowest total compressor losses calculated from compressor losses of the compressor at selected environmental operating conditions weighted based on an estimated time spent at each operating condition over the life of the compressor; or 
 a highest compressor efficiency for the compressor calculated in accordance with an efficiency standard using environmental operating conditions set by the efficiency standard, 
 wherein the compressor losses are calculated based on at least one of an area above a polytropic curve at the selected environmental conditions for an under-compression of the refrigerant or the area below the polytropic curve at the selected environmental conditions for an over-compression of the refrigerant. 
   
     
     
         2 . The system of  claim 1 , wherein the selected environmental operating conditions are selected based on estimating the operating conditions for the compressor at a selected geographic location. 
     
     
         3 . The system of  claim 1 , wherein the selected environmental operating conditions are selected based on an efficiency standard. 
     
     
         4 . The system of  claim 1 , wherein the highest compressor efficiency for the compressor calculated in accordance with the efficiency standard using environmental operating conditions set by the efficiency standard is based on the refrigerant and the weighted environmental operating conditions of a group of compressor volume ratios. 
     
     
         5 . The system of  claim 4 , wherein the total compressor losses and compressor efficiency are calculated for compressor volume ratios within a range of 1.5 to 3.5. 
     
     
         6 . The system of  claim 1 , wherein:
 the single fixed volume ratio compressor is a multi-stage compressor having a first compressor volume ratio for a first compressor stage and a second compressor volume ratio for a second compressor stage; and   the compressor volume ratio is further determined based on the first and second compressor volume ratios,   wherein the first compressor volume ratio is determined based on the thermodynamic properties of the refrigerant and a first set of selected environmental operating conditions; and   wherein the second compressor volume ratio is determined based on the thermodynamic properties of the refrigerant and a second set of selected environmental operating conditions.   
     
     
         7 . The system of  claim 1 , wherein the compressor losses are determined at two, three, five, or more selected environmental conditions. 
     
     
         8 . The system of  claim 1 , wherein the compressor losses are normalized based on the refrigerant. 
     
     
         9 . A method for installing a heating, ventilation, and air-conditioning (“HVAC”) system, the method comprising:
 installing a single fixed volume ratio compressor operable to compress a refrigerant, the single compressor having a compressor volume ratio designed by:
 determining the compressor volume ratio based on thermodynamic properties of the refrigerant and at least one of:
 the lowest total compressor losses calculated from compressor losses of the compressor at selected environmental operating conditions weighted based on an estimated time spent at each operating condition over the life of the compressor; or 
 a highest compressor efficiency for the compressor calculated in accordance with an efficiency standard using environmental operating conditions set by the efficiency standard, 
 wherein the compressor losses are calculated based on at least one of an area above a polytropic curve at the selected environmental conditions for an under-compression of the refrigerant or the area below the polytropic curve at the selected environmental conditions for an over-compression of the refrigerant. 
 
 
 
     
     
         10 . The method of  claim 9 , wherein the selected environmental operating conditions are selected based on estimating the operating conditions for the compressor at a selected geographic location. 
     
     
         11 . The method of  claim 9 , wherein the selected environmental operating conditions are selected based on the efficiency standard. 
     
     
         12 . The method of  claim 9 , wherein the highest compressor efficiency for the compressor calculated in accordance with the efficiency standard using environmental operating conditions set by the efficiency standard is based on the refrigerant and the weighted environmental operating conditions of a group of compressor volume ratios. 
     
     
         13 . The method of  claim 9 , wherein the total compressor losses and compressor efficiency are calculated for compressor volume ratios within a range of 1.5 to 3.5. 
     
     
         14 . The method of  claim 9 , wherein:
 the single fixed volume ratio compressor is a multi-stage compressor having a first compressor volume ratio for a first compressor stage and a second compressor volume ratio for a second compressor stage; and   determining the compressor volume ratio further comprises:
 determining the first compressor volume ratio based on the thermodynamic properties of the refrigerant and a first set of selected environmental operating conditions; and 
 determining a second compressor volume ratio based on the thermodynamic properties of the refrigerant and a second set of selected environmental operating conditions. 
   
     
     
         15 . The method of  claim 9 , wherein the compressor losses are determined at two, three, five, or more environmental conditions. 
     
     
         16 . The method of  claim 9 , wherein the compressor losses are normalized based on the refrigerant.