Fault-tolerant multi-node stage sequencer and method for energy systems

• US 20020193890A1
• Filed: 12/15/2000
• Published: 12/19/2002
• Est. Priority Date: 12/15/2000
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Pouchak, Michael A.
• Granted Patent: US 6,745,085 B2
• Time in Patent Office: Days
• US Class Current: 700/21
• CPC Class Codes: F23N 2231/30 Representation of working time
• CPC Class Codes: F23N 2237/02 two or more burners
• CPC Class Codes: F23N 5/24 Preventing development of abnormal or undesired conditions, i.e. safety arrangements F23N5/02 - F23N5/18 take precedence
• CPC Class Codes: F24D 19/1006 for water heating systems
• CPC Class Codes: F24D 2200/043 More than one gas or oil fired boiler

Abstract

A method for controlling energy systems such as multiple boiler systems to meet an energy need includes a controller configured as a sequencer with the remaining controllers act as individual boiler controllers which periodically send status messages to the sequencer. The energy need is determined by measurements at the sequencer which maintains runtimes of the boilers. The sequencer periodically sends control commands to the boiler controllers to add or delete boilers. The control commands give consideration to the run times of the boilers.

Claims

1. A method of controlling a plurality of energy systems to meet an energy need comprising the steps of:

providing controllers;

configuring said controllers with one controller acting as a sequencer and the remaining controllers acting as energy system controllers;

determining said energy need based on measurements at said sequencer;

said energy system controllers periodically sending status messages;

receiving and storing said status messages at said sequencer;

maintaining a record of runtimes of said energy systems;

sending periodic control commands from said sequencer to said energy system controllers to add or delete energy systems based on said energy need.

2. The method of claim 1 wherein said energy systems are capable of a variable output and said step of sending periodic control commands further comprises sending a command to vary said output of said energy system.

3. The method of claim 1 wherein said step of sending periodic control commands from said sequencer to said energy system controllers to add or delete energy systems based on said energy need comprises the step of selecting an energy system to be added based on runtimes of available energy systems.

4. The method of claim 1 wherein said step of sending periodic control commands from said sequencer to said energy system controllers to add or delete energy systems based on said energy need comprises the step of compensating for a first energy system that is selected to be added but is not available for operation by adding a second energy system to meet said energy need.

5. The method of claim 2 wherein said energy systems are boilers having a variable firing rate.

6. The method of claim 2 wherein said energy systems are water heaters having a variable firing rate.

7. The method of claim 1 wherein said step of sending periodic control commands from said sequencer to add or delete energy systems comprises the steps of:

turning on an energy system when the presently operating energy systems are operating at a first capacity and are not meeting an energy need; and

turning off an energy system when the first boiler turned on among said presently operating energy systems is operating at a second capacity with said second capacity being less than said first capacity.

8. The method of claim 1 wherein said step of sending periodic control commands from said sequencer to add or delete energy systems comprises the steps of:

turning on an energy system having the lowest runtime among available energy systems when adding an energy system; and

turning off an energy system that was the first energy system turned on among presently operating energy systems when deleting an energy system.

9. The method of claim 7 wherein the highest efficiency of an energy system occurs when said energy system is operating at a first capacity and said step of turning on an energy system comprises the step of adding an energy system when said added energy system can operate at said first capacity and satisfy said energy need.

10. The method of claim 7 wherein said first capacity is a minimum capacity.

11. A system for controlling a plurality of boilers comprising:

a first controller acting as a sequencer node;

a plurality of second controllers acting as boiler nodes, with each second controller connected to one of said plurality of boilers;

said sequencer node and said boiler nodes configured for network communication of control information;

means at said sequencer node for determining a heating need;

means at said sequencer node for receiving status and runtime information from said boiler nodes and maintaining a record of said runtime; and

means at said sequencer node for turning on a boiler or turning off a boiler based on said heating need with selection of said boiler at least partially based on equalizing runtimes of said plurality of boilers with said system compensating for a boiler that is not operational by selecting an alternate boiler.

12. The system of claim 11 wherein each boiler of said plurality of boilers is capable of variable output and said system further comprises means for sending periodic control commands to vary an output of said boiler.

13. The system of claim 11 wherein said means for turning on a boiler or turning off a boiler comprises turning off a boiler that was the first boiler turned on among presently operating boilers when deleting a boiler.

14. The system of claim 11 wherein said means for turning a boiler on or turning a boiler off comprises turning on a boiler having the lowest runtime among boilers not presently operating when adding a boiler.

15. The system of claim 11 wherein said means for turning a boiler on or turning a boiler off comprises means for evaluating the efficiency of an alternative number of operating boilers.