Water circulation structure of fuel gas corner tube hot-water boiler

Abstract

The invention provides a water circulation structure of a fuel gas corner tube hot-water boiler. Rising flow is completely forced by a heat-absorbing face and possible tube burst accidents caused by hydraulic working condition deterioration such as subcooled boiling, stagnating and backflow are avoided. A boiler body is of a frame-type self-supporting structure composed of large-diameter steel tubes arranged on the four corners, an upper collecting box, a lower collecting box, a longitudinal collecting box and a transverse collecting box; the water circulation structure is composed of a water cooling wall of a front wall of a furnace hearth, a water cooling wall of a rear wall of the furnace hearth, a membrane-type water cooling wall heat-absorbing face of a side wall I, a membrane-type water cooling wall heat-absorbing face of a side wall II, a membrane-type water cooling wall heat-absorbing face of a side wall III, a conversion shaft membrane-type water cooling wall heat-absorbing face, a flag-type heat-absorbing face, a collection box and connection pipes between the water cooling wall of the front wall of the furnace hearth, the water cooling wall of the rear wall of the furnace hearth, the membrane-type water cooling wall heat-absorbing face of the side wall I, the membrane-type water cooling wall heat-absorbing face of the side wall II, the membrane-type water cooling wall heat-absorbing face of the side wall III, the conversion shaft membrane-type water cooling wall heat-absorbing face, the flag-type heat-absorbing face and the collection box. The flag-type heat-absorbing face which does not penetrate through the walls is directly welded to the densely-arranged membrane-type water cooling wall of the rear wall, so that the transverse pitches of tube bundles are reduced and reasonable smoke flow speed is guaranteed; two side walls are divided into three levels of heat-absorbing faces according to different heat loads, so that heat deviation and flow deviation in the water tubes are greatly reduced. The boiler body is composed of the full-membrane-type water cooling walls, the conversion tube bundles do not penetrate through the walls, the air-tightness is good, the air leakage amount is small, the burning efficiency is high, and the water circulation structure can safely and efficiently operate for a long time under various loads.

Description

technical field [0001] The invention relates to the technical field of boiler equipment, in particular to a water circulation structure of a gas corner tube hot water boiler. Background technique [0002] In recent years, with the discovery of several new large natural gas fields in China, such as Longgang, Dabei, and Keshen, more and more small coal-fired hot water boilers have been replaced by gas-fired boilers. Compared with coal-fired boilers, gas-fired boilers can fundamentally solve many environmental problems such as dust, waste water, waste residue, and harmful gas emissions. Among them, the corner-tube gas-fired hot water boiler has the advantages of reasonable structure, less raw material consumption, safe and reliable long-term operation, high efficiency, energy saving, emission reduction and environmental protection, and will definitely become the first choice of gas-fired hot water boiler in my country. [0003] However, the existing angle tube technology has t...

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Problems solved by technology

[0004] 1) In the traditional corner tube hot water boiler, when the flue gas flows through the heating surface at the tail of the flue, due to the large flow cross-sectional area, the flow velocity is low, resulting in poor heat exchange between the flue gas and the heating surface, and convection at the tail The temperature of the medium in the heating surface is too low, and the wall temperature of the heating surface is often lower than the acid dew point temperature of the flue gas, resulting in low-temperature corrosion of the convective heating surface tubes, which seriously affects the safe operation of the boiler

[0005] 2) For forced circulation hot water boilers operating on the market, in most cases, partitions are arranged inside the upper and lower headers of the membrane water-cooled wall to divide the entire heating surface of the water-cooled wall into circulation loops flowing upward and downward , when the downward-flowing circulation loop operates at low load and suddenly loses power, there will inevitably be hydrodynamic conditions such as stagnation of water circulation and reverse flow. The existence of such conditions seriously threatens the operation safety of hot water boilers. Therefore, the existing The low load and power failure protection problems that may occur in the forced circulation mode have seriously affected the popularization and application of advanced technology products

The application number is: 201110212423.6, and the name of the invention is a corner tube water circulation structure with all forced upward flow on the heating surface (the publication number is CN102374658A). The one-time forced upward flow of the header is not conducive to the uniform distribution of the working fluid in the header to the water-cooled wall tubes, and the reduction of flow deviation and heat dissipation for boilers with large-area side wall membrane water wall heating surfaces. deviation

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