HVAC CONTROL SYSTEM AND METHOD

• US 20120259469A1
• Filed: 12/15/2010
• Published: 10/11/2012
• Est. Priority Date: 12/16/2009
• Status: Active Grant

• Current Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Original Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Inventors: Ward, John, Wall, Joshua, Platt, Glenn
• Granted Patent: US 9,429,923 B2
• Time in Patent Office: Days
• US Class Current: 700/276
• 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 11/47 Responding to energy costs
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• 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 11/63 Electronic processing
• CPC Class Codes: F24F 2120/00 Control inputs relating to users or occupants
• CPC Class Codes: F24F 2120/20 Feedback from users
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G05B 2219/2614 HVAC, heating, ventillation, climate control
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: G05D 23/1917 using digital means

Abstract

A method of controlling the heating, ventilation and air conditioning (HVAC) system of a building, the method comprising the steps of: (a) developing an initial thermal model of the building, and continuously updating the thermal model over time; (b) utilising the thermal model to continuously develop a daily HVAC operating plan for the building; and (c) continuously examining a current HVAC operating plan and optimising the alignment of the current HVAC operation with the current HVAC operating plan.

Claims

1. A method of controlling the heating, ventilation and air conditioning (HVAC) system of a building, the method comprising the steps of:

(a) developing an initial thermal model of the building, and continuously updating this thermal model over time;

(b) utilising the thermal model to continuously develop a daily HVAC operating plan for the building; and

(c) continuously examining a current HVAC operating plan and optimising the alignment of the current HVAC operation with the current HVAC operating plan.

2. A method as claimed in claim 1 wherein said thermal model utilises a series of parameters, fitted to historical thermal data for the building.

3. A method as claimed in claim 1 wherein said thermal model is a piecewise polynomial model.

4. A method as claimed in claim 1 wherein said initial thermal model is iteratively updated substantially daily.

5. A method as claimed in claim 1 wherein said daily HVAC operating plan is recalculated substantially every 5 minutes.

6. A method as claimed in claim 1 wherein said optimising the alignment of said HVAC operation with the current HVAC operating plan is attempted substantially every 10 seconds.

23. A method according to of claim 1, wherein the thermal model has substantially the following form:

24. A method according to claim 23 wherein the baseline function changes depending on the current day of the week.

25. A method according to claim 24 wherein the baseline function is formed of a combination of triangular basis functions that are estimated at specific fixed points throughout a day.

26. A method as claimed in claim 1 wherein said controlling of said HVAC utilisation with the current HVAC operating plan is attempted substantially in increments of seconds.

28. A method according to claim 1, wherein the thermal model has substantially the following form:

T_z=F_A(s)·

T_Amb+BaselineFcn−

F_T(s)·

Δ

T_SS

where;

T_z is (modelled) aggregate zone temperature;

T_Amb is the outside (Ambient) air temperature;

Δ

T_SS is the steady state difference in zone temperature that would result from the current HVAC cooling and heating powers;

BaselineFcn is a learnt function of time, accounting for people, equipment, sun, etc;

F_A(s) and F_T(s) are linear time invariant filters, accounting for the system dynamics.

29. A method as claimed in claim 28 wherein Δ

T_SS has the form;

Δ

T_SS=α

_c·

μ

_c·

max{0,P_cool−

P_cb}−

α

_h·

μ

_h·

max{0,P_HeatP_hb}

where the first part of the equation is the effective cooling temperature (Δ

T_Cool), the second part is the effective heating temperature (Δ

T_Heat), and the parameters are;

P_Cool and P_Heat are estimates of actual cooling and heating powers respectively (kW);

P_cb and P_hb are baseline cooling and heating powers respectively (kW);

α

_c and α

_h are nominal scaling for HVAC power effectiveness (°

C./kW); and

μ

_c and μ

_h are HVAC efficiency de-ratings as a function of external temperature.

7-13. -13. (canceled)

14. A method of controlling the heating, ventilation and air conditioning (HVAC) system of a building, the method comprising the steps of:

(a) determining a thermal model for the building;

(b) determining expected external meteorological conditions for an area surrounding the building;

(c) determining an external meteorological condition model for the HVAC system;

(d) utilising the external meteorological condition model as the prime factor in calculating an HVAC operating plan of the building.

15. A method as claimed in claim 14 wherein said external meteorological condition model is augmented with data from meteorological data suppliers.

21. A method as claimed in claim 14 wherein said thermal model is iteratively updated substantially daily.

22. A method as claimed in claim 14 wherein said HVAC operating plan is recalculated substantially in increments of minutes.

16. A method of controlling the heating, ventilation and air conditioning (HVAC) system of a building, the method comprising the steps of:

(a) determining a thermal model for the building;

(b) determining an expected human comfort model for users of the building;

(c) determining a power consumption or carbon emission model for the HVAC system;

(d) determining a energy cost model for the HVAC system;

(e) determining an external meteorological condition model for the HVAC system;

(f) applying relative weightings of two or more of the expected human comfort model, power consumption or carbon emission model, energy cost model, and external meteorological condition model for the HVAC system in calculating an HVAC operating plan of the building.

17. A method as claimed in claim 16 wherein said human comfort model is augmented with personal comfort data of users of the building by means of data feed back from users of the building.

18. A method as claimed in claim 16 wherein said human comfort model is derived from the ASHRAE standard comfort models.

19. A method as claimed in claim 16 wherein said power consumption or carbon emission model and said energy cost model is augmented with consumption and pricing data from energy suppliers.

20. (canceled)

27. (canceled)