Method and apparatus for retarding scale formation of water heating boiler by utilizing reflux dilution turbulence

Abstract

A method for diluting disturbance and slowing down scaling of a hot water boiler by using refluence and a device thereof belong to the field of boiler plants. The device comprises a hot water boiler (1), a booster water pump (3), a refluence by-pass pipe (4), and a water circulating pump (7). The invention is characterized in that the invention is realized by the mode that part boiler outlet water circulates, reflows in a back-flow by-pass pipe, and then blends with new boiler inlet water to be transported to the hot water boiler: (1) scaling ion concentration of the boiler inlet water is reduced; (2)water flow velocity in a heat exchange tube of the boiler is increased; the scouring and peeling on scaling layers of tube walls is strengthen; (3) inlet temperature is increased; scaling reacts ahead of time; scaling deposition shifts to the inlet of the heat exchange tube; scaling intensity of the back end of the heat exchange tube is reduced; homogenizing distribution of the scaling layers can effectively prolong about 30% to 60% of formation time of blockage caused by pipeline scaling, the effect of which can greatly surpass effect generated by flow velocity increment and ion concentration reduction. The superimposing of the three effects causes that formation time of blockage caused by pipeline scaling is greatly prolonged; the period of cleaning and contaminant separation is prolonged more than 50 %.

Description

technical field [0001] The invention belongs to the field of boiler equipment, and in particular provides a method and device for alleviating and reducing fouling. Background technique [0002] Dirt is a layer of solid deposits on the heat transfer surface after the heat exchange equipment has been in operation for a period of time. The main cause of fouling is the precipitation and adhesion of solutes and organic matter on the heat exchange surface. Scaling on the inner wall of boiler heat exchange tubes is a serious problem affecting industrial production. Fouling (or fouling) has two main effects on heat exchange equipment: (1) Due to the low thermal conductivity of the fouling layer, it increases the heat transfer resistance and reduces the heat transfer efficiency of heat exchange equipment; ( 2) The formation of the fouling layer reduces the flow area of ​​the fluid channel in the heat exchange equipment, resulting in increased flow resistance, thereby consuming more...

AI Technical Summary

Problems solved by technology

In 1974, West Germany first used the patented technology of rotating helix to enhance heat transfer and anti-fouling. It is to set a rotating helix in each heat transfer tube of the shell-and-tube heat exchange equipment to scrape the dirt on the inner wall. The disadvantage of this technology is that the structure is complex, external driving force is required, the descaling function is single, and the transplantability is weak

Since the 1960s and 1970s, researchers have begun to explore the introduction of multiphase fluidization technology into the anti-scaling and descaling process, by adding a certain type, concentration, and particle size of inert solid particles to the heat exchange device to achieve enhanced heat transfer and The purpose of anti-scaling and descaling has achieved obvious results. This technology needs to install complex particle addition equipment and continuous solid particle supply, which is costly and economical.

For example, for the fouling of hot water boilers in oilfield blending systems, mechanical dredging is often used. Frequent cleaning every 2-3 months requires a lot of manpower, material and financial resources, especially in Daqing and Liaohe oilfields. Very hard cleaning

Images