Method for operating variable speed heat pumps and air conditioners
First Claim
1. A method for operating a system having variable speed equipment such as heat pumps and air conditioners while (1) achieving optimal comfort conditions in an air conditioned space and (2) maximizing the coefficient of performance (COP) of said equipment;
- said equipment being characterized by having controls for varying equipment parameters thereof including compressor speed (r), indoor air flow rate (c), and evaporator superheat (t);
said system having multiple sensory inputs from which variable comfort influencing data parameters transmitted from said space to said equipment includes dry-bulb temperature (T), humidity ratio (w) and air velocity (V);
said method comprising the steps of;
providing a nonlinear measure of comfort function CI (T,w,V) based on said data parameters;
setting one of said data parameters and calculating default values for the other of said data parameters;
calculating a set point value for said comfort function;
expressing said function CI (T,w,V) in terms of said equipment parameters as a function of IC (r,c,t);
calculating a comfort error (CE) value which is set point value of CI (T,w,V) minus said CI (r,c,t);
selecting a nonlinear coefficient of performance function PE (r,c,t) based on said equipment parameters which is desired to be maximized and which is based on the same variables as said CI (r,c,t); and
setting said controls to effect maximizing said PE (r,c,t) function while maintaining said (CE) value at substantially a zero value.
1 Assignment
0 Petitions
Accused Products
Abstract
A controller and a related method that maintains thermal comfort in an occupied space at a user-defined level while simultaneously maximizing the efficiency of the space conditioning equipment. The controller determines the setting of heating/cooling capacity, indoor airflow rate, evaporator superheat and other system parameters such that a comfort constraint is satisfied. The comfort index may be any arbitrarily-defined relationship of measured or inferred quantities such as air temperature, relative humidity, air velocity, mean radiant temperature, CO2 concentration, etc. The controller ensures that the error between comfort index and the comfort setpoint is zero while the energy consumed by the space conditioning equipment is minimized.
-
Citations
10 Claims
-
1. A method for operating a system having variable speed equipment such as heat pumps and air conditioners while (1) achieving optimal comfort conditions in an air conditioned space and (2) maximizing the coefficient of performance (COP) of said equipment;
-
said equipment being characterized by having controls for varying equipment parameters thereof including compressor speed (r), indoor air flow rate (c), and evaporator superheat (t); said system having multiple sensory inputs from which variable comfort influencing data parameters transmitted from said space to said equipment includes dry-bulb temperature (T), humidity ratio (w) and air velocity (V); said method comprising the steps of; providing a nonlinear measure of comfort function CI (T,w,V) based on said data parameters; setting one of said data parameters and calculating default values for the other of said data parameters; calculating a set point value for said comfort function; expressing said function CI (T,w,V) in terms of said equipment parameters as a function of IC (r,c,t); calculating a comfort error (CE) value which is set point value of CI (T,w,V) minus said CI (r,c,t); selecting a nonlinear coefficient of performance function PE (r,c,t) based on said equipment parameters which is desired to be maximized and which is based on the same variables as said CI (r,c,t); and setting said controls to effect maximizing said PE (r,c,t) function while maintaining said (CE) value at substantially a zero value. - View Dependent Claims (2, 3, 4, 5)
-
3. A method as set forth in claim 1 wherein said variable comfort influencing data parameters include CO2 concentration, particulates and other air contaminants.
-
4. A method as set forth in claim 1 wherein said dry-bulb temperature (T) is set.
-
5. A method as set forth in claim 1 wherein said other of said data parameters are initially adjustable to provide a bias thereon.
-
-
6. A method for operating a system having variable speed equipment such as heat pumps and air conditioners while (1) achieving optimal comfort conditions in an air conditioned space and (2) maximizing the coefficient of performance (COP) of said equipment;
-
said equipment being characterized by having controls for varying parameters thereof; said system having multiple sensory inputs from which variable comfort influencing data parameters are transmitted from said space to said equipment; said method comprising the steps of; providing a nonlinear measure of comfort function CI (data) based on said data parameters; setting one of said data parameters and calculating default values for the other of said parameters; calculating a set point value for said comfort function CI (data); expressing said comfort function CI (data) in terms of said equipment parameters as a comfort function CI (manipulated control variables); calculating a comfort error (CE) value which is said set point value of said CI (data) minus said CI (manipulated control variables); selecting a nonlinear performance function PE (manipulated control variables) based on said equipment parameters which is desired to be maximized and which is based on the same variables as said CI (manipulated control variables); and setting said controls to effect maximizing said PE (manipulated control variables) function while maintaining said (CE) value at substantially a zero value. - View Dependent Claims (7, 8)
-
8. A method according to claim 6 wherein said comfort error (CE) and said set point value are continuously updated.
-
-
9. A method for operating a system having variable speed equipment such as heat pumps and air conditioners while (1) achieving optimal comfort conditions in an air conditioned space and (2) maximizing the coefficient of performance (COP) of said equipment;
-
said equipment being characterized by having controls for varying equipment parameters thereof including compressor speed (r), indoor air flow rate (c), and evaporator superheat (t); said system having multiple sensory inputs from which variable comfort influencing data parameters transmitted from said space to said equipment includes dry-bulb temperature (T), humidity ratio (W) and air velocity (V); said method comprising the steps of; providing a nonlinear measure of comfort feature CI (T,w,V) based on said data parameters; setting one of said data parameters and calculating default values for the other of said data parameters; calculating a set point value for said comfort function; expressing said function CI (T,w,V) in terms of said equipment parameters as a function of CI (r,c,t); calculating a comfort error (CE) value which is said set point value of CI (T,w,V) minus said CI (r,c,t); selecting a nonlinear coefficient of performance function PE (r,c,t) based on said equipment parameters which is desired to be maximized and which is based on the same variables as said CI (r,c,t); representing said PE function as a performance index L(x,u) and representing said CE function as a constraint function f(x,u); setting said controls to effect maximizing said PE (r,c,t) function while maintaining said (CE) value at substantially a zero value, said maximizing being effected by relating said functions through a performance index (H) wherein H=L(x,u)+λ
T ·
f(x,u) with said λ
T being a Lagrangian multiplier, and x being state parameters and said u being a decision vector; andfinding values of said decision vector at a stationary value of said L(x,u) wherein dL=0 for arbitrary du while holding df=0.
-
-
10. A method for operating a space conditioning system having equipment characterized by variable operating parameters which both (1) achieves desired comfort conditions in the conditioned space and (2) maximizes the performance efficiency of said equipment, said equipment being characterized by controls for varying operating parameters thereof, said system having multiple sensory inputs from which a plurality of actual time-variable comfort influencing data parameter values are transmitted from said conditioned space to said equipment on a real-time basis, said system also having user-determined desired data parameter values;
- said method comprising the steps of;
calculating a desired comfort index set point based on said user determined desired data parameter values; calculating an actual comfort index value based on said actual time-variable comfort influencing data parameter values; calculating an equipment performance function based on said variable operating parameters and said desired comfort index set point; and adjusting said variable operating parameters of said equipment so as to maximize said equipment performance function while attempting to maintain said desired comfort index set point.
- said method comprising the steps of;
Specification