A plurality of water heaters are connected in parallel with respect to a hot water supply path, and each of the plurality of water heaters has an exhaust path connected to an exhaust path assembly. Each of a plurality of sensing units is configured to be shifted from an electrically conducting state to an electrically non-conducting state when each of the plurality of sensing units senses an abnormal condition about air supply or exhaust. A series circuit of the plurality of sensing units is electrically connected in series to a resistance element between the power supply line and the ground line. The controller is configured to monitor an abnormal condition about air supply or exhaust based on a voltage on a node between the series circuit and the resistance element.

The current invention discloses a method and apparatus for production of hot water or steam in a 4-pass firetube boiler. A waste heat stream is passed through the first and second passes of the boiler, and then routed into a furnace tube (which is the third pass of the boiler) to help suppress the flame temperature and NOx emissions from the burner. The flue gas from the third pass is then passed through the fourth pass of the boiler to transfer the heat energy to the water in the boiler.

There is provided an AI-based air damper control system and method for industrial boilers. An AI-based optimal air damper control method according to an embodiment calculates energy efficiency under a given control condition and an environment by extracting energy efficiency-related data from industrial boiler operational data and analyzing a correlation between corresponding data, trains an AI-based optimal air volume-for-load prediction model by using the extracted data and the calculated energy efficiency as training data, and derives an air volume condition that results in peak energy efficiency under a given load, based on the trained optimal air volume-for-load prediction model, and automatically controls the air damper according to the corresponding air volume condition.

A solute concentration decision method for deciding a planned value C.sub.I of a concentration of a solute in a solution to be supplied to a first drum among one or more steam drums for temporarily containing steam generated in a boiler of a steam turbine plant includes a step of deciding the planned value C.sub.I of the concentration of the solute in the solution to be supplied to the first drum, on the basis of a target concentration of the solute in the solution in the first drum and a capacity coefficient of the solute in a drum unit including the first drum and an evaporator for generating steam contained in the first drum.

A method is disclosed for anticipating operation characteristics of a steam generation system, the steam generation system comprising at least one boiler. The method comprises conducting a fuel analysis of a solid fuel and anticipating the at least one operation characteristic of the steam generation system at the time when a specific partial quantity of solid fuel is combusted in the furnace of a boiler of the steam generation system, and further determining at least one adapted setpoint of at least one operation parameter of the steam generation system dependent upon the fuel composition of any specific solid fuel partial quantity so as to counteract and/or remedy changes of the at least one operation characteristic which are caused by the fuel composition of the specific solid fuel partial quantity. The method may be employed to improve operation of a steam generating system when the fuel composition varies.

A method is disclosed for anticipating operation characteristics of a steam generation system, the steam generation system comprising at least one boiler. The method comprises conducting a fuel analysis of a solid fuel and anticipating the at least one operation characteristic of the steam generation system at the time when a specific partial quantity of solid fuel is combusted in the furnace of a boiler of the steam generation system, and further determining at least one adapted setpoint of at least one operation parameter of the steam generation system dependent upon the fuel composition of any specific solid fuel partial quantity so as to counteract and/or remedy changes of the at least one operation characteristic which are caused by the fuel composition of the specific solid fuel partial quantity. The method may be employed to improve operation of a steam generating system when the fuel composition varies.

Provided are a method and system for improving control of a steam generator level for preventing oscillation of the steam generator level in a nuclear power plant. In order to prevent oscillation of a steam generator level and resultant shutdown of a nuclear reactor, which may be caused when a high-level priority control function is frequently and repeatedly turned on/off as the steam generator level is excessively increased, by improving a feedwater control system in the nuclear power plant, a proportional integral control value may be controlled to be reduced, and thus, output while a certain condition is met after a high-level priority mode is deactivated or a signal instructing to enter the high-level priority control mode may be controlled not to be output.

A steam vaporizer assembly includes an internal steam generator having a vessel configured to hold water, a vaporizer unit having a heating element configured to heat the water to generate saturated steam; and a controller configured to: cause the heating element to heat the water to a stand-by temperature; and while maintaining a water level of the water in the vessel between two control points: maintain the water in the vessel at the stand-by temperature until steam generation is required, and when steam generation is required, heating the water in the vessel from the stand-by temperature to a temperature at or above a vaporization temperature of the water using a heating element, to generate the steam.

A steam vaporizer assembly includes an internal steam generator having a vessel configured to hold water, a vaporizer unit having a heating element configured to heat the water to generate saturated steam; and a controller configured to: cause the heating element to heat the water to a stand-by temperature; and while maintaining a water level of the water in the vessel between two control points: maintain the water in the vessel at the stand-by temperature until steam generation is required, and when steam generation is required, heating the water in the vessel from the stand-by temperature to a temperature at or above a vaporization temperature of the water using a heating element, to generate the steam.

An electric steam generating device includes a cast body, a heating element, and a fluid passage. The heating element is at least partially surrounded by the cast body. The fluid passage passes through the cast body and is spaced apart from the heating element. The cast body transfers heat from the heating element to the fluid passage, and the fluid passage includes a first portion having a first size and a second portion having a second size.