Tube assembly for a boiler

Abstract

A boiler is described comprising a housing with a flue gas inlet for receiving a hot gas flame and an outlet for venting a hot gas produced by the hot gas flame, and a tube assembly mounted within the housing. The tube assembly comprises a lower manifold for receiving a liquid, an upper manifold for receiving a heated version of the liquid; and, a plurality of tubes disposed between the lower and upper manifolds. Each tube is shaped to provide a hot gas pathway that travels in a parallel fashion along at least a lower portion of the longitudinal extent of each tube in the tube assembly to the outlet, whereby the liquid introduced into the lower manifold travels in the plurality of tubes and receives heat from the hot gas along the extent of the hot gas pathway.

Description

FIELD OF THE INVENTION [0001] The invention relates to a design for improving heat transfer and system efficiency for a boiler. BACKGROUND OF THE INVENTION [0002] A boiler is a pressurized system in which heat is transferred to a fluid. Water is typically used as the fluid for economical reasons and its suitable thermodynamic characteristics. The water is heated by heat transferred to the water from a source of higher temperature (i.e. a flue gas), which is usually produced by the combustion of fuels. The water may be heated to a suitable temperature or heated such that it is vaporized to a steam. Accordingly, connections are made for the off-take of the heated water or the generated steam and for the replenishment of water. The heated water or generated steam can be used as a heating medium or as a working fluid in another device that converts thermal energy to mechanical work. The water also acts to cool the heat-absorbing surfaces of the boiler while the water circulates through ...

AI Technical Summary

Benefits of technology

[0006] The inventors have realized that it is possible to increase the efficiency of a boiler by using a unique, parallel flow design in which the flow of the flue gas (i.e. hot gases) is parallel to the direction of at least a portion of the tube runs of the water tubes. This orientation allows for more direct radiant heat towards the water tubes resulting in greater heat transfer coefficients and improved system efficiency. In addition, the orientation allows for a smaller flow path, and thus a smaller size boiler, for producing the same amount of heat as compared to a larger, conventional boiler. The inventors have also found that it is advantageous to fire a flue gas flame directly towards an end wall composed of tubes of a portion of the tube assembly for more direct heat transfer as well as removing the need for refractory material in this portion of a boiler.

Problems solved by technology

However, to obtain a higher throughput of heated water or generated steam, either a higher efficiency boiler is needed, which, if conventionally designed, results in increased costs due to the need for additional more expensive equipment, or a larger boiler is needed which also results in increased costs due to the need for more material.

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