Domestic cooling tower industry technology trends
Release date：2018/1/9
Crossflow towers as a form of cooling tower (the other is a countercurrent tower) in recent years has gradually withdrawn from the industrial tower market, in the civilian tower market (central air conditioning unit package) still occupies a considerable share. Countercurrent tower Advantages: At present the technical status of the cooling tower, the countercurrent tower has been superior to the cross flow tower in many aspects due to the appearance of the membrane packing and the improvement of the countercurrent tower pneumatic technology. Even then, a large number of towers in China to sell cross-tower business, their alternative technology is counter-current tower. The countercurrent cooling tower's market share has now exceeded 80% of the cooling tower's entire market. 1, water in the tower packing, the water from top to bottom, the air from the bottom up, the two flow to the opposite of a cooling tower. 2, the counter-current cooling tower thermal performance is good, divided into three cooling sections: ① water distributor to the top of this space, the higher the water temperature, so the heat can still be passed to the air. ② packing water and air heat exchange section. ③ filler to catchment pool water shower, water is cooled in this section called "tail effect." In northern China water temperature can drop 1-2 ℃. In summary, the countercurrent tower than the cross-flow tower in the same case, the packing volume is about 20% smaller, counter-current tower heat exchange process more reasonable cooling efficiency. 3, the water distribution system is not easy to block, water and padding to keep clean and not easy to aging, moisture reflux, antifreeze ice measures easier. Multiple combinations can be designed, the water temperature in winter to the required amount of water can be combined with the Taiwan operation or stop the fan. 4, construction and installation easy maintenance, low cost, commonly used in air conditioning and industrial large and medium-sized cooling circulating water. Cooling tower water filler is a traditional cooling tower heat exchange of the main components, it is directly related to the quality of the cooling tower effect, but there are contradictions in the choice of filler: good heat dissipation of the filler, the ventilation resistance, ventilation resistance Small packing its cooling capacity is poor. Shortcomings of cross-flow towers: the fifties and sixties cross-flow cooling towers are better use, from the mid-70s, the oil and chemical industry new cooling tower almost all cross-flow tower. By the early 1990s, the new industrial cooling tower was almost an all-new countercurrent tower because it saved energy compared to the cross-flow cooling tower. In addition to finding a new cooling method, it is more important to improve the cooling efficiency and save energy. So nearly half a century, its progress is not fast, from here you can see the development of cooling technology and energy-saving internal relations. Transformation of the old tower usually refers to the cooling tower in disrepair, the Department, the component damage or aging, a serious decline in output, must be promptly repaired, in most cases due to the cooling tower to take what is missing, what to make, what to change, what to change, Only to restore the original cold effect. In recent years, cooling tower design technology has been greatly improved, spare parts and materials are upgrading, so many old towers across the country, tapping the potential through transformation, energy-saving a lot of space, which is a huge cooling tower market. From the cooling tower of the technical application level, tapping the transformation of new tower design is more difficult than high. As the saying goes: "White paper can be used for the most beautiful picture," while the tapping transformation, it is necessary to make full use of the original conditions and equipment, such as: fan and its transmission system and the existing structure, but also to reach above The original design of the output, and some need to increase the temperature difference or reduce the water temperature, it is necessary to see the inadequacies of the design of the old tower, but also the advanced technology and the retained equipment and accessories coordination, there is indeed a certain degree of difficulty . However, there have been many examples of successful retrofits. For example, the original water flow rate of fan counterflow towers of 5m * 8m and Φ4.7m in cross section is 360 ~ 400m3 / h, and the retrofit capacity is increased to 670 ~ 950m3 / h with an output increase of 87% ~ 138%. Φ8.0m reinforced concrete cross-flow tower, after the transformation of the output increased by 40%; Φ9.13m, 17m * 17m section of the "Harmon" introduction of the counter-current tower to upgrade the ability to upgrade 33%, and so on. Naturally, there are also inefficiencies that arise from new conditions associated with the use of new technologies and new components, such as changes in flow regimes, matching of system resistance, or the availability of certain components Use, but with the new accessories is not the best combination, etc., relying solely on thermal calculation and Qigong calculations, far from solving the problem, so accurate grasp of the new situation resulting from the combination of old and new, and adopt the appropriate countermeasures cooling tower tapping transformation The key, in addition to the retained equipment and fittings and their status quo must grasp and understand, if necessary, repair and adjustment. This transformation can tap the potential to achieve more obvious results, it can be said that the potential of tapping the potential for tapping the potential energy of the old tower is far greater than that of the new tower when it is being built, hoping to arouse the public's attention. Cooling tower packing with the increase of running time, especially in the conditions of high concentration multiples run, recycled water, calcium and magnesium salts and microorganisms continue to attach to the surface of the filler, affecting the cooling effect. Filler debris will block the heat exchanger tube bundle, affecting the heat transfer effect. ① water collector does not cover all the filler, water droplets splash loss. With a small tank capacity, can not increase the amount of water. ③ As the tower's load-bearing part of the steel structure, while supporting the Φ = 9140m fan base, 2 fans at the same time easy to produce tower resonance, as well as the amplitude caused by excessive fan stop. ④ air inlet blinds serious winter icing, and both sides of the wall to form a tight air tight box, to a large extent, can only rely on the road to cool the cold air, but also because of air and water than the limit, so the cooling efficiency is low . ⑤ cooling tower water treatment and pump water does not match. ⑥ center point because of the tower plane fan support column, and the overflow to form a reflux zone, so that the sterilization process of sterilization and exfoliation suspended solids formed on the surface of the water is difficult to discharge outside the system. Spray ventilation cooling tower in the MSG application will be gradually promoted. MSG industry's energy consumption is mainly water, electricity, steam three. With the continuous economic development and water conservation requirements, the application of circulating cooling tower in the industry is a universal and indispensable device. In the past, most of the enterprises used the cooling tower of packing and electric fan combination for recycling the cooling water of fermentor and condensing pump.
