Detail problems needing attention in Energy-saving Operation of Industrial Boiler in Chemical Plant
Details that should be paid attention to in energy saving operation of industrial boilers in chemical plants 1. Fuel thickness and injection mode control for coal burning laminar combustion boilers, in the actual operation process, the size of particles in the same coal seam is different and the distribution is unreasonable. Ventilation is uneven and combustion is uneven. The uniform layer combustion coal feeding method can be used to improve the incomplete combustion of coal seam: large particle coal is first added to the lower layer, followed by small particles in the upper layer, and the surface area of the large particle coal is the smallest, which takes a long time to burn. At this time, it is in the lower layer with the highest oxygen concentration in the air. On the contrary, small fine coal has large surface area, low oxygen concentration and full utilization of excess coal. Air��
The excess air coefficient of air door and air volume is too large, the smoke exhaust loss is large, the excess air coefficient is too small, and the incomplete combustion loss is large, so it is necessary to adjust the air volume reasonably to minimize the loss of the above two items. Generally, smoke analyzer detection is carried out at the tail flue exhaust, and the air volume is controlled to reduce carbon monoxide to a reasonable value. For unconditional flue gas analysis, we can judge by naked eye experience, look at the flame in the furnace, the flame whitens, indicating that the air surplus is large, the flame is brown and not transparent, smoke exhaust smoke indicates that the combustion is incomplete.
3. When there is 1mm thick scale on the heating surface of boiler on the surface of water quality management experiment, the waste of fuel is about 3% ~ 5%, and when there is 3mm thick scale, the waste of fuel is about 5% ~ 10% [3]. There are two general steps in water treatment: pretreatment, ion exchange or reverse osmosis.
4. After the ash cleaning ash or scale is deposited on the heating surface, the heat transfer and thermal resistance increases, the heat absorption on the pipe wall decreases, the smoke temperature at the furnace outlet increases, and the boiler output decreases, so the amount of coal added has to be increased. Cause furnace outlet smoke temperature to further increase to form a vicious circle. Therefore, timely ash cleaning is particularly important.
The energy efficiency test of the thermal insulation to the industrial gas steam boiler shows that the heat dissipation loss of the small-sized boiler is about 3% when the heat preservation is good, and if the material selection of the heat-insulating material is wrong, the thickness is small, even the damage is damaged, the heat-insulating property is not covered locally, the heat dissipation loss is higher, The boiler has been running, causing heat to be wasted in the air. Check whether the heat-insulating brick of the furnace wall falls off when the boiler is shut down; check whether the flue-isolating brick is complete, and avoid the short-circuit of the flue gas; the outer surface of the boiler body, the steam pipeline and other parts are damaged and damaged in time; and when the heat-insulating and heat-preservation is carried out, A material with a small thermal conductivity (that is, a material with good thermal insulation properties) is placed in the inner layer. It has better insulation effect; if conditions permit, the surface of economizer should be laid with insulation layer.
6. solving the problem of boiler air leakage is a common problem in the operation of boiler units. It is necessary to ensure the tightness of the boiler. First of all, it is necessary to check the furnace wall, furnace door, inspection hole and other loose parts, which can be lit by candle method. Light candles near these places and see if the candle flame deflects inward to judge. Secondly, there is air leakage on the tail heating surface, most of which are cracks at the welding joint of the flue, the bend of the elbow, and the wear and tear of the expansion joint. Most of the air superheaters cause air leakage due to corrosion or wear through the pipe, which should be checked when the boiler is shut down.
