System and Method for Controlling Operations of Air-Conditioning System

• US 20160258645A1
• Filed: 05/18/2015
• Published: 09/08/2016
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Grover, Piyush, Kramer, Boris, Boufounos, Petros T., Benosman, Mouhacine
• Granted Patent: US 10,145,576 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/65 for selecting an operating mode
• CPC Class Codes: F24F 11/79 for controlling the direction of the supplied air
• CPC Class Codes: F24F 2110/00 Control inputs relating to air properties
• CPC Class Codes: G05B 13/04 involving the use of models or simulators
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G05D 23/1917 using digital means

Abstract

A method determines values of the airflow measured in the conditioned environment during the operation of the air-conditioning system and selects, from a set of regimes predetermined for the conditioned environment, a regime of the airflow matching the measured values of the airflow. The method selects, from a set of models of the airflow predetermined for the conditioned environment, a model of airflow corresponding to the selected regime and models the airflow using the selected model. The operation of the air-conditioning system is controlled using the modeled airflow.

Claims

1. A method for controlling an operation of an air-conditioning system generating airflow in a conditioned environment, comprising:

determining values of the airflow measured in the conditioned environment during the operation of the air-conditioning system;

selecting, from a set of regimes predetermined for the conditioned environment, a regime of the airflow matching the measured values of the airflow;

selecting, from a set of models of the airflow predetermined for the conditioned environment, a model of airflow corresponding to the selected regime;

modeling the airflow using the selected model; and

controlling the operation of the air-conditioning system using the modeled airflow, wherein steps of the method are performed using at least one processor of a controller.

2. The method of claim 1, wherein the values of the airflow include velocity and temperature measurements of the airflow at a set of locations in the conditioned environment, and wherein the selecting the regime comprises:

comparing a function of the values of the airflow against constraints representing a structure of each predetermined regime.

3. The method of claim 2, further comprising:

determining, using the measured values, partial information of a pattern of movement of the airflow in the controlled environment; and

comparing the partial information with corresponding values of patterns of each regime to select the best regime matching the measured values of the airflow.

4. The method of claim 1, further comprising:

comparing the measured values of the airflow with patterns of each regime using a compressed sensing to select the regime best matching the measured values of the airflow.

5. The method of claim 1, further comprising:

determining a set of regimes of the airflow by parametrizing patterns of the airflow arising from different configurations and boundary conditions in the control environment; and

comparing the measured values of the airflow with each regime using a compressed sensing to select the matching regime.

6. The method of claim 1, wherein each regime in the set of regimes of the airflow is represented as a block of basis elements;

and

comparing the measured values of the airflow with each regime using compressed sensing to select the matching regime according to

7. The method of claim 6, wherein the blocks of basis elements include approximation of Koopman eigenmodes determined as eigenvectors of a dynamic mode decomposition (DMD).

8. The method of claim 6, wherein the blocks of basis elements are augmented with time evolution of the basis elements based on eigenvalues of a dynamic mode decomposition (DMD) representing dynamics of the basis elements.

9. The method of claim 8, further comprising:

selecting the regime iteratively using the values of the airflow measured at multiple instances of time by comparing the augmented basis elements with the values of the airflow changing over the multiple instances of time.

10. The method of claim 1, wherein the controlling comprises:

changing a state of at least one component of the air-conditioning system.

11. The method of claim 1, wherein the controlling comprises:

updating at least one control input for at least one component of the air-conditioning system to optimize a metric of performance determined using the model.

12. The method of claim 1, wherein the controlling changes a vent angle of the air-conditioning system.

13. The method of claim 1, further comprising:

updating the model of airflow connecting values of flow and temperature of the airflow conditioned during the operation of the air-conditioning system, wherein the updating iteratively reduces an error between values of the airflow determined according to the model and the measured values of the airflow.

14. The method of claim 1, wherein the model includes a reduced order model having a number of parameters less than a physical model of the airflow according to a Boussinesq equation, wherein the Boussinesq equation is a partial differential equation (PDE), and wherein the reduced order model is an ordinary differential equation (ODE).

15. The method of claim 14, wherein the model includes a stability parameter representing a difference between the reduced order model and the physical model, and wherein the updating comprises:

updating only the stability parameter of the model in response to detecting the error.

16. A system for controlling an air-conditioning system generating a flow of fluid in a conditioned environment, comprising:

a set of sensors for measuring values of the flow in the conditioned environment;

a memory storing a set of regimes of fluid dynamic in the conditioned environment and a corresponding set of models of flow dynamics connecting values of velocity and temperature of fluid conditioned during the operation of the system; and

a controller for controlling the operation of the system based on a modeled flow, wherein the controller includes a processor for selecting a regime matching the measured values of the flow, for selecting a model corresponding to the selected regime, and for determining the modeled flow using the selected model.

17. The system of claim 16, wherein the air-conditioning system generates the flow of air in the conditioned environment, and wherein the air-conditioning system comprises:

an evaporator having a fan for adjusting an air-flow rate through a heat exchanger;

a condenser having a fan for adjusting the air-flow rate through the heat exchanger;

a compressor having a speed for compressing and pumping refrigerant through the system; and

an expansion valve for providing an adjustable pressure drop between a high-pressure portion and a low-pressure portion of the vapor compression system.

18. The system of claim 16, wherein each model includes a reduced order model having a number of parameters less than a physical model of the airflow and a stability parameter representing a difference between the reduced order model and the physical model, and wherein the processor updates the stability parameter of the selected model in response to detecting an error an error between values of the flow determined according to the selected model and the values of the flow measured during the operation.

19. An air-conditioning system, comprising:

a user input interface for receiving a setpoint;

a set of sensors for measuring values of airflow in the conditioned environment;

an evaporator having a fan for adjusting an airflow rate through a heat exchanger;

a condenser having a fan for adjusting the airflow rate through the heat exchanger;

a compressor having a speed for compressing and pumping refrigerant through the system;

an expansion valve for providing an adjustable pressure drop between a high-pressure portion and a low-pressure portion of the vapor compression system;

a memory storing a set of regimes of fluid dynamic in the conditioned environment and a corresponding set of models of flow dynamics connecting values of velocity and temperature of the airflow conditioned during the operation of the system; and

a controller for controlling the operation based on a modeled airflow to achieve the setpoint, wherein the controller includes a processor for selecting a regime matching the measured values of the airflow, for selecting a model corresponding to the selected regime, and for determining the modeled flow using the selected model.

20. The system of claim 19, wherein the model includes a reduced order model having a number of parameters less than a physical model of the airflow, and a stability parameter representing a difference between the reduced order model and the physical model, and wherein the processor updating only the stability parameter of the model in response to detecting an error between values of the airflow determined according to the selected model and the values of the airflow measured during the operation.