A method for improving effectiveness of a steam generator system includes providing air to an air preheater at a mass flow such that the air preheater has a cold end outlet temperature defined by the improved air preheater operating with increased heat recovery (HR) of at least 1% calculated according to the equation: HR=100%?((Tgi?TgoAdvX)/(Tgi?TgoSTD)?1). The method requires either reducing the amount of heat that flows into the air preheater from the flue gas and/or increasing the amount of heat extracted from the flue gas. The method includes mitigating SO.sub.3 in the flue gas which is discharged directly from the air preheater to a particulate removal system and then directly into a flue gas desulfurization system. The method includes extracting heat from the Flue gas to create equipment preheat and/or flue gas stack reheat air with the latter being fed to heat the flue gas prior to entering a discharge stack to raise the temperature of the flue gas to mitigate visible plume exiting and to mitigate corrosion in, the discharge stack.

A preheating system for preheating fluid medium to be fed into the HRSG is disclosed. The system includes a feed line and a recirculation line. The feed line is adapted to feed the fluid medium to a Low Pressure Economizer (LPE) of the HRSG. The feed line is adapted to be adjoined to an inlet of the LPE, and an outlet of the LPE enables therefrom the flow of the fluid medium in further portion of the HRSG. The recirculation line is adapted to be connected between the outlet and the inlet of the LPE, in parallel to LPE to recirculate the fluid medium to the LPE. A particular method of preheating using such a system is equally disclosed.

The present disclosure relates to a flue gas exhaust system for an industrial furnace, especially a steam reforming furnace. The flue gas exhaust system comprises a stack having an inlet opening for introducing flue gas into the stack and an outlet opening for exhausting flue gas. The inlet opening of the stack is in fluid connection to an outlet of a heat recovery system of the industrial furnace. Further, the fluid connection between said heat recovery system outlet and said stack inlet opening comprises a transition flue gas duct that at least partly embraces a part of the stack.

The present disclosure relates to a flue gas exhaust system for an industrial furnace, especially a steam reforming furnace. The flue gas exhaust system comprises a stack having an inlet opening for introducing flue gas into the stack and an outlet opening for exhausting flue gas. The inlet opening of the stack is in fluid connection to an outlet of a heat recovery system of the industrial furnace. Further, the fluid connection between said heat recovery system outlet and said stack inlet opening comprises a transition flue gas duct that at least partly embraces a part of the stack.

A method of preventing high temperature corrosion on a heat exchanging surface of a biomass boiler, including: a first feeding step, supplying a first biomass fuel to the boiler; a deposition step, performing combustion on the first biomass fuel during initial operation of the boiler, and forming an inert deposition layer on a surface of a heat exchanger of the boiler; a second feeding step, supplying a second biomass fuel different from the first biomass fuel to the boiler; and a normal combustion step, performing combustion on the second biomass fuel. A direct contact of an alkali metal chloride with a metal pipe wall is prevented by forming an inert deposition layer on the surface of the heat exchanger of the boiler in the deposition step, thereby establishing a physical barrier between the heat exchanging surface and the alkali metal chloride to prevent corrosion on the metal pipe wall.

One or more embodiments of the present invention relate to a pump/heat exchanger assembly of a nuclear reactor, in particular a liquid metal cooled nuclear reactor, the pump being characterized in that the shaft for driving the impeller is inserted in an shell inside the heat exchanger and has a smaller cross section at the bottom part of the tube bundle of the heat exchanger and a cross section that gradually increases up to a widest cross section at the top part of the tube bundle of the heat exchanger. The resulting axial profile of the impeller's shaft is, at the same time, designed to uniformly distribute the flow of the primary fluid inside the tube bundle of the heat exchanger and to provide high mechanical inertia to the pump.

In a method for reducing the oxygen content in the flow volume of tubes of erected and installed tube wall regions or tube wall segments of a steam generator or steam boiler of a power station fired, in particular, with carbon-containing fuel, a solution is to be provided which eliminates or at least diminishes the problem of the incorporation of atmospheric oxygen into the boiler water which arises when tubes of the steam generator wall are being filled with boiler water and/or when boiler water is being discharged from these tubes. This is achieved in that an inert gas or an inert gas mixture is introduced into tubes of the tube wall regions or tube segments, through which boiler water or steam formed from this flows when the power station is in operation, before filling with boiler water or steam, in a way whereby gaseous oxygen present in the respective flow volume of the tubes, particularly in the form of atmospheric oxygen, is displaced, and/or an inert gas or an inert gas mixture is introduced during a discharge of boiler water or steam from the respective flow volume of the tubes, in a way whereby the free volume occurring is filled.

The invention relates to a domestic water heating system, which comprises: (A) a main water tank; and (B) an accelerator having a sleeve, which in turn comprises a mechanism for flushing lime scale accumulated at the bottom of the internal hollow of the sleeve, said mechanism causes a flow of cold-water from a cold-water inlet, to said bottom of the internal hollow of the sleeve, and from there to the main tank via hollows in the sleeve.

The present invention relates to a closed circuit (10) operating on a Rankine cycle, said circuit comprising at least one compression and circulation pump (12) for a working fluid in liquid form, a heat exchanger (18) over which a hot source (23) is swept in order to evaporate said fluid, means (26) for expanding the fluid into the form of a vapor, a cooling exchanger (34) swept by a cold source to condense the working fluid, a reservoir (40) of working fluid, and working fluid circulation pipes (44, 46, 50, 52, 54) for circulating said fluid between the pump, the heat exchanger, the expansion means, the condenser and the reservoir.

According to the invention, the circuit comprises a device (56) for draining the fluid contained in the heat exchanger (18).

In the case of a method for the heat treatment of erected, preferably large-area tube wall regions or tube wall segments, in particular of a diaphragm wall, of a steam generator, in particular of a power plant, in the installed state, it is sought to provide a solution which permits the use of steel types which are more problematic with regard to power plant operation with elevated steam parameters, in particular the steels T23 and T24, in the erection of steam generators. This is achieved in that the tube wall regions or tube wall segments for heat treatment are subjected, in the installed state in the steam generator, and in particular over a large area, to a stress-relief annealing process.