1. A method for optimizing soot cleaning operations in a boiler of a power generating unit, wherein the boiler is divided into a plurality of zones, the method comprising: using communications interfaces to transmit current operating conditions of the power generating unit to a zone selection component of a computer-based optimization system for soot cleaning, said current operating conditions including current operating conditions associated with soot cleaning devices and the boiler; using the zone selection component to select one of said plurality of zones of the boiler for a soot cleaning operation given said current operating conditions of the power generating unit, wherein said zone selection component is programmed to select one of said plurality of zones of the boiler by executing the following steps: accessing an expert system comprised of (1) an inference engine, (2) a first knowledge base comprising a plurality of propose rules, wherein each of said plurality of propose rules has associated therewith: (a) one or more trigger conditions, (b) one or more enabling conditions indicative of whether soot cleaning can be currently initiated in a zone of the boiler, and (c) a proposed action having an associated rank, and (3) a second knowledge base comprising a plurality of apply rules; using the inference engine for evaluating the plurality of propose rules to generate a list of proposed actions for achieving boiler performance goals for operation of the boiler, wherein each proposed action identifies a zone for a soot cleaning operation, wherein the proposed action associated with a propose rule is added to the generated list of proposed actions only when the following conditions are satisfied: (a) the trigger conditions associated with the propose rule and (b) the enabling conditions associated with the propose rule, and wherein satisfaction of the trigger conditions and enabling conditions are determined using the current operating conditions transmitted by the communications interfaces; using the inference engine for evaluating the plurality of apply rules of the second knowledge base to select one proposed action from the generated list of one or more proposed actions determined by evaluating the plurality of propose rules, wherein said one proposed action is selected from the generated list of proposed actions according to the rank associated with each proposed action; using a soot cleaning device selection component of the computer-based optimization system for selecting at least one soot cleaning device within the zone identified by the selected proposed action; and using a soot cleaning device controller for activating the at least one selected soot cleaning device.