White fog produced by cooling tower directly affects the image of enterprise, adding huge pressure of enterprises for environmental protection;
As the evaporation of cooling tower causes the waste of water, with the implementation of ladder-like water price policy, water bill increases dramatically.
With current serious fog and haze, pollutants are easily attached to the vapor surface of cooling tower, causing increasingly serious haze;
With scarcity of water resources, the evaporation loss of industrial circulating water is one of the main reason for wasting water;
Cooperative University: North China University of Water Resources and Electric Power
Leader: Professor Wang / Post-doctoral
R&D time：Start to R&D in 2012/ the first device putting into operation successfully in 2013
Achievements: 10 Invented Patents and Utility Model Patents/Software copyrights
2 Drafting corporate standards / getting experiment report /
international advanced-level appraised by leading experts
Development history of R&D
The first Generation of Technology
Finned-tube bundle is placed on drift eliminator within the tower, small type of circulating water pump is used to put backwater of cooling tower into finned-tube bundle for circulation, making the wet air of cooling tower condensate outside of bundle as a way to realize fog dispersal and water conservation.
Why give up this technology?
When the quality of circulating water is poor, with perennial contact between wet steam and finned-tube bundle with serious scaling and it is hard to clean with current technology。 Heat-conducting property of finned-tube bundle after scaling is greatly reduced, the performance of fog dispersal and water saving is severely degraded, and the function of fog dispersal and water saving will be basically lost。
The Second Generation of Technology
Technical Introduction: the front-end precooling technology (so-called dry-wet combined technology), arrange openings on the panel of both sides of air chamber on the upper of drift eliminator to install finned-tube bundle, put backwater of cooling tower into finned-tube bundle for pre-cooling. As the water temperature is declined after pre-cooling when arriving at filling section of cooling tower, causing heat exchange relatively reduced as a way to realize fog dispersal and water conservation. This technology has already used in 1970s in America. We have optimized this technology and make it engineering. After that, the device runs relatively good with obvious effect of fog dispersal.
Why give up this technology? Due to Poor quality of circulating water, the internal finned-tube bundle is easy to be scaling; Influenced by investment, the material of heat exchange pipe is carbon steel, which is easy to be corrosion and damaged. fin-pitch of finned-tube bundle is small (generally within 3mm), the external debris (catkin, sand and dust) is vulnerable to enter fin under the excitation of fan, causing clog. Internal fan frequently contacts with internal wet and humid air, which is easy to be corrosion, greatly affecting the effect of heat exchange and it is hard to clean with current technology; Finned-tube bundle is easy to be icing in winter, causing crack of tube, adding maintenance costs.
The Third Generation of Technology:
Technology introduction: the module is used for deep condensate water demisting device to put it within the cooling tower and the main material is superconductive carbon. Newly-built cooling tower with 1000m3 in Dongying, Shandong province and renovated cooling tower with 3000m3 in Cangzhou, Hebei Province have operated for nearly three years, which have presents obvious effect of fog dispersal and water saving with stable operation and completely reached the design requirements。
12 sets of newly-built fog dispersal cooling towers with 4000M3 for Cangzhou railway have put into operation, which is the largest tower group with independent technology. The rate of demisting and water saving of This kind of cooling tower has reached the design requirements, greatly outperforming the other types of technologies for cooling tower, and this technology has been already awarded with patent for invent and multiple Utility Mode Patents.
Operating principle: based on the basic theory of condensing heat exchange, heat-conduction and convective heat and mass transfer, water vapor after heat exchange of cooling tower circulating water will be deeply condensed to film through convection and heat conduction and heat exchange so as to collect it for re-circulation, effectively improving the availability of circulating water, meanwhile providing high quality of pure water resources to reduce the formation of haze.
The device is arranged and designed when newly-built the cooling tower, and also used for the renovation of old tower, which is constructed and commissioned by our company to ensure the energy efficient operation of the device.
Drawing of Operating principle for Fog dispersal and water saving cooling tower
Ambient air going through Wet packing
Saturated hot air going through a pair of alternating heat exchange plate
Ambient air going through inlet pipe
Outer air going through a pair of alternating heat exchange plate
Saturated air from wet cold air mixed with dry air from outer dry cold air
Tower outlet air
Condensation and water saving: one side of device is wet air with approximately saturated state, after entering into condensation device, convective heat transfer will be made between wet air and dry cold air on the other side of heat exchange plate, at this time, the temperature of wet and humid air reduces, making the temperature and pressure of water vapor within wet air reach the limited state, water vapor is condensed precipitated from wet air to attach to heat exchange plate, when drops on plate meeting specific conditions, drops will be fell into water tank or collected and exported from heat exchange plate, achieving the goal of water saving。
Newly-built cooling tower
It is Calculated based on 20% of annual average recovery rate of vapor (taking circulating water with 1000 m3/h as example)
The annual average evaporation capacity is calculated based on 1。5%, 20% for drift eliminator rate, the annual operating hours is 8000h and the industrial water price is counted based on 5RMB/m3, thus the efficiency of water saving is:
Water saving: water will be increasingly constraint in future industries and production. Currently, industrial park has basically implemented stepped water price, with the expansion of industry volume, it is difficult to buy water, thus water saving is much crucial.
Fog dispersal: White smoke greatly damages the environment protection image of enterprises, when functional departments monitors the discharges of industries and enterprises, it is hard to differentiate the discharged is white smoke, vapor or exhaust gas.
Reducing the generation of haze: the haze is generated by dust particles and organic waste attaching to vapor, reducing the discharge of fog, it means the generation of haze.
Reducing operation cost: water saving is the reuse of pure water, reducing the concentration multiple of circulating water, adding the times of circulation and reducing the use of pollutant discharge and agent.
Load: as module is light, it doesn’t need to add additional load during the design and construction of cooling tower。
Energy consumption: based on tracking and measurement, the energy consumption can be ignored as it basically doesn’t increase。
Inspection: install within the tower with rational position。 Inspection channel is convenient for inspection and will not affect other parts (fan and reducer)。