Water circulation structure of a gas corner tube hot water boiler

Abstract

A water circulation structure of a gas-fired corner tube hot water boiler with forced upward flow on all heating surfaces, which avoids tube burst accidents that may occur due to deterioration of hydrodynamic conditions such as supercooled boiling, stagnation, and backflow; the boiler body is composed of large-diameter Frame-type self-supporting structure composed of steel pipes and upper, lower, vertical and horizontal headers; water circulation structure consists of water-cooled walls at the front and rear walls of the furnace, side walls Ⅰ, Ⅱ, and Ⅲ membrane-type water-cooled walls for heating surfaces, convection shaft membrane-type water-cooled walls The heating surface, the flag heating surface, the header and the connecting pipes between them are composed. The flag heating surface that does not pass through the wall is directly welded to the densely packed rear wall membrane water wall to reduce the transverse pitch of the tube bundle and ensure a reasonable smoke flow. The air flow rate; the walls on both sides are divided into three heating surfaces according to the different heat loads, which greatly reduces the heat deviation and flow deviation in the water pipe. The boiler body is composed of a full-membrane water-cooled wall. The convection tube bundle does not penetrate the wall. It has good air tightness, less air leakage, and high combustion efficiency. It can operate safely and efficiently for a long period of 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-fired corner-tube hot water boiler. Background technique [0002] In recent years, with the discovery of several new large-scale natural gas fields such as Longgang, Dabei, and Keshen in China, more and more small coal-fired hot water boilers have been replaced by gas-fired boilers.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 hot water boiler has the advantages of reasonable structure, low consumption of raw materials, safe and reliable long-term operation, high efficiency, energy saving, emission reduction and environmental protection, and will definitely become the first choice for gas hot water boilers in my country. [0003] However, the existing corner tube technology ...

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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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