Methods and apparatuses for control of building cooling, heating and power co-generation systems

• US 20060116789A1
• Filed: 12/01/2004
• Published: 06/01/2006
• Est. Priority Date: 12/01/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Subramanian, Dharmashankar, Mathur, Anoop K.
• Granted Patent: US 7,567,859 B2
• Time in Patent Office: Days
• US Class Current: 700/275
• CPC Class Codes: F24F 11/47 Responding to energy costs
• CPC Class Codes: F25B 27/02 using waste heat, e.g. from internal-combustion engines
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: Y02A 30/274 using waste energy, e.g. from internal combustion engine
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]
• CPC Class Codes: Y02P 80/15 On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply

Abstract

A control system and method for achieving economic operation of CHP systems. A plurality of factors, including power source prices and operational needs, are assessed using multiple strategies. The solutions achieved by each strategy are compared, and the best performing strategy is selected. The solution can then be implemented. The assessment of factors and strategies can be updated periodically. A further embodiment includes a method of designing a CHP system using similar methods applied to simulated or estimated future loads and costs.

Claims

1. A controller for controlling a CHP system, the system including a local generator for electricity, a fuel source, connections to an external electric power source, and a number of operational components including heating and cooling devices, the controller configured to perform the steps of:

estimating future load conditions for thermal and power loads;

performing a first analysis using a first operational strategy to generate a first future cost figure for the cost of operating the CHP system;

performing a second analysis using a second operational strategy to generate a second future cost figure for the cost of operating the CHP system;

comparing the first future cost figure to the second future cost figure; and

selecting the operational strategy corresponding to the lesser cost figure.

2. A controller as in claim 1 wherein the controller is configured to perform the step of performing the first cost analysis by including consideration of usage costs for the operational components.

3. A controller as in claim 1 wherein the controller is configured to perform the step of estimating future load conditions using a method including the steps of:

using data related to the operational components; and

using data related to environmental conditions for the CHP system.

4. A controller as in claim 1 wherein the controller is configured for use in a CHP system including a turbine generator, a boiler, an absorption cooler, a heat recovery steam generator, and an electric chiller.

5. A controller as in claim 4 wherein the controller is configured to perform analysis using at least:

an operational strategy in which the preferred cooling source is the absorption chiller;

an operational strategy in which the preferred cooling source is the electric chiller.

6. A controller as in claim 4 wherein the controller is configured to perform analysis using at least:

an operational strategy in which the preferred electricity source is the turbine generator; and

an operational strategy in which the preferred electricity source is the external electric power source.

7. A controller as in claim 1 wherein the step of estimating future load conditions for thermal and power loads comprises:

accessing a database of historical load conditions; and

estimating future load conditions for the next hour.

8. A CHP system comprising a number of operational components adapted to provide heating, cooling, and power, and a controller as recited in claim 1, the controller coupled to the operational components to provide control signals thereto.

9. A method of operating a CHP system for providing electric power and thermal control to a facility, the CHP system including a number of operational components adapted to provide cooling, heating, and/or power, the method comprising:

estimating future load conditions for thermal and power loads for the CHP system;

performing a first analysis using a first operational strategy to generate a first future cost figure for the cost of operating the CHP system;

performing a second analysis using a second operational strategy to generate a second future cost figure for the cost of operating the CHP system;

comparing the first future cost figure to the second future cost figure; and

selecting the operational strategy corresponding to the lesser cost figure.

10. The method of claim 9 wherein the steps of performing analyses using the first and second operational strategies further include considering usage costs of components in the CHP system.

11. The method of claim 9 wherein the step of estimating future load conditions comprises:

accessing a database of historical load conditions; and

estimating future load conditions for the next hour.

12. The method of claim 9 wherein the steps of performing analyses using the first and second operational strategies comprise:

using data related to fuel and electricity prices;

using data related to the operational components; and

using data related to environmental conditions for the CHP system.

13. The method of claim 9 wherein the method further comprises sending control signals to a turbine generator, a boiler, an absorption cooler, a heat recovery steam generator, and an electric chiller.

14. The method of claim 13 wherein:

the first operational strategy is one in which the preferred cooling source is the absorption chiller; and

the second operational strategy is one in which the preferred cooling source is the electric chiller.

15. The method of claim 13 wherein:

the first operational strategy is one in which the preferred electricity source is the turbine generator; and

the second operational strategy is one in which the preferred electricity source is the external electric power source.

16. A method of operating a CHP system for providing electric power and thermal control to a facility, the method comprising:

observing prices for a plurality of power/fuel sources;

observing likely load conditions for the facility;

performing a first cost analysis using a first strategy for operation of the CHP system;

performing a second cost analysis using a second strategy for operation of the CHP system;

selecting an operational strategy in light of the first and second cost analyses.

17. The method of claim 16 further comprising configuring the CHP system for the operational strategy.

18. The method of claim 16 wherein the CHP system includes:

a gas turbine;

an absorption chiller; and

a heat recovery steam generator;

wherein the step of configuring the CHP system includes distributing load levels for the gas turbine, the absorption chiller, and the heat recovery steam generator.

19. The method of claim 18 wherein the CHP system is coupled to an electric grid, wherein the step of configuring the CHP system includes modulating power drawn from the electric grid.

20. The method of claim 16 wherein the steps of performing the first cost analysis and the second cost analysis include consideration of the usage costs of components of the CHP system.

21. A method comprising periodically performing the method of claim 16.

22. The method of claim 21 wherein the step of periodically performing occurs hourly.

23. A controller for a CHP system, the controller configured to perform the method of claim 16.

24. A method of designing a CHP system, the CHP system including components chosen from a collection of available components, the method comprising:

choosing a first combination of components from among those available;

performing a first cost estimate the first combination of components using a first operational strategy;

performing a second cost estimate for the first combination of components using a second operational strategy;

selecting between the first operational strategy and the second operational strategy for the first combination of components in light of the first and second cost estimates;

choosing a second combination of components from among those available;

performing a first cost estimate for the second combination of components using the first operational strategy;

performing a second cost estimate for the second combination of components using the second operational strategy;

selecting between the first operational strategy and the second operational strategy for the second combination of components in light of the first and second cost estimates; and

selecting between the first combination of components and the second combination of components in light of the chosen operational strategy and estimated cost associated with each.

25. The method of claim 24 wherein the steps of selecting between operational strategies are performed repeatedly for a number of anticipated operational conditions, wherein the step of selecting between the first combination of components and the second combination of components includes considering an aggregated cost for each combination of components which includes a number of first and second cost estimates.