Why is the shape of the cooling tower so designed and what are the advantages? This question is actually very easy to confuse people, because various factors are intertwined, in fact, there are several different problems in the middle:

First. The earliest cooling towers had various shapes, such as straight cylinders and octagonal cylinders;

Second. Hyperboloid tower
After Iterson first invented the hyperboloid tower in 1915, this configuration quickly became popular in thermal power stations. And with the emergence of large thermal nuclear power plants, there is this kind of natural ventilation hyperboloid cooling tower.

This is a chain of relationships: 1. Increase in installed capacity of power stations — 2. Need to build a larger-scale cooling tower — 3. Cooling capacity is directly affected by area and height, so cooling towers are taller and larger — 4. The tall cylindrical structure is very unstable, and the cost is very high even if it is built-5. It is necessary to use economic means to build a large cooling tower-6. The hyperboloid tower is the most economical;

All thin-shell curved structures have the characteristics of high strength and material saving. There are also cooling towers of other shapes and materials. The exploration of the structure is endless. At present, a typical large cooling tower is about 150m high, and its bottom diameter is about 150m, that is, its bottom can accommodate a football field. However, its thickness is very thin, only 20cm at its thinnest point. If the cooling tower is scaled down to the diameter of the egg shell, it will be thinner than the egg shell, only 1/5 of the thickness of the egg shell.

Third. Why is the hyperboloid structure the most economical?
First of all, according to the structure of the cooling tower, it can be seen that the narrowed design in the middle makes the area of ​​the air inlet larger under the same water spray area, which helps increase the air volume. Therefore this surface should be curved inward.
The reason for the economy of hyperboloids is not because of the most saving of materials, but because of the way it is constructed. Hyperboloids are a kind of ruled curved surfaces that are composed of a straight line through continuous motion, which is its most important geometric property. The straight line rotates around an axis to form a hyperboloid. Therefore, the steel bars do not need to be bent when arranged, that is, they are parallel to the oblique straight line in space. Of course, nowadays, with the increase in size, the construction method of the hyperbolic cooling tower is to cast the concrete in sections.

After years of engineering practice, the mechanical properties and wind-proof performance of this structure have been well tested, and it has become the most common form of cooling tower. Therefore, the use of hyperboloids is also a historical inertia. In fact, in engineering practice, the construction is not completely based on the geometric shape of the curved surface. In actual construction, the curved surface is mostly constructed in sections. Given the radius and thickness of the cylinder wall generatrix, the multi-section flat steel template is used to approximate it. Therefore, strictly speaking, its final shape is different from the hyperbolic busbar. Today’s tower shape is the result of the mutual influence of optimized design, engineering practice and construction habits, and it is different from the geometrical hyperboloid.

For a long time, the income from power generation has been the main income of enterprises in the waste incineration field. Among them, the payers of power generation revenue are mainly the two power grid companies. Among the fees paid, part of the cost is paid by the power grid company with reference to the local benchmark power generation price. In addition, the state will generate 280 kWh per ton of garbage and implement local thermal power per kWh. Benchmark electricity price + 0.25 yuan/kWh subsidy renewable energy subsidy price, that is, the standard subsidy of 0.65 yuan per kilowatt-hour of electricity, through the power grid company, on behalf of the waste incineration enterprises; electricity exceeding 280 kWh is normally sold at the local benchmark electricity price. At the same time, the value-added tax of waste incineration power plants will be refunded immediately, and the income tax will be subject to a preferential policy of three exemptions and three halves. Starting from the tax year in which the project obtains the first production and operation income, the corporate income tax will be exempt from the first to the third year, and the corporate income tax will be reduced by half from the fourth to the sixth year.

The benefits of waste incineration are a very cost-effective thing for local governments. Therefore, since 2016, waste incineration projects have been rapidly launched in various places. According to incomplete statistics, there were only more than two hundred waste incineration plants nationwide in 2016. Today, four years later, there are 486 waste incineration enterprises nationwide. However, with the accompanying increase in public anxiety, and the increase in the amount of waste incineration on the atmospheric environment, the emission risks and growth potential of persistent organic pollutants, dioxins, have become increasingly prominent.

Our country’s thinking on waste treatment has been relatively clear from single incineration to comprehensive waste classification and full-stage classification treatment, reducing the amount of waste incineration treatment, and increasing non-incineration treatment and resource utilization methods. Because of this, it is possible to reduce the persistent organic matter emissions caused by waste incineration, such as dioxins and polycyclic aromatic hydrocarbons, to a greater extent. As a result, the relevant subsidy thinking has also undergone a huge adjustment. The weight ratio of harmlessness such as regulatory emission reduction has increased, and the weight ratio of resource utilization such as power generation has decreased, which has become the main direction of subsidies. In the new plan, three important subsidy policy orientations are reflected:

First, state subsidies will gradually withdraw, and local finances must fill the gap;
Second, the subsidies that waste incineration companies can receive for new projects in the future are no longer the previous quotas. They must compete with other peer companies in price competition and corporate operating technology strength, with strong operating capabilities and low electricity sales prices. Companies can receive electricity price subsidies, and this subsidy should be subject to different local policy conditions, and the amount of subsidy received by each company may be different;
Third, in the future, national and local financial subsidies will be more inclined to the front, middle and back ends of waste sorting, and more emphasis will be given to non-electric and other energy supply fields that are more market-oriented or require incineration companies to develop themselves.

To sum up, these adjustments will bring huge challenges to the profit model and operation model of waste incineration companies!

To solve the sludge problem, it is the consensus of the industry to “dispose” and decide “treatment”. Drawing on international experience, there are four main paths for the technical development of sludge treatment and disposal in the future:

(1) Anaerobic digestion technology route based on biogas energy recovery and land utilization
It is generally believed that the cost of anaerobic digestion is low, and sludge reduction and stabilization can be achieved. According to the statistics of “China Environment News”, the investment cost of simple anaerobic digestion is about 200,000 to 400,000 yuan/(ton/day). The cost is saved due to the lack of blast aeration. The operating cost of simple anaerobic digestion is about 60- 120 yuan/ton (80% moisture content, excluding concentration and dehydration), and the operating cost of aerobic fermentation is 120-160 yuan/ton.
More than 50% of the sludge in Europe and the United States is treated by anaerobic digestion, and the generated biogas can be converted into electricity to meet 33% to 100% of the electricity required by the sewage plant. However, the application of sludge anaerobic digestion in my country is not smooth. Of the approximately 50 sludge anaerobic digestion facilities built in China, only more than 20 can operate stably. The main reasons are the poor quality of sludge and the low level of operation and management of treatment plants in my country.
In recent years, research and practice have shown that pretreatment of sludge through alkaline hydrolysis, heat treatment, ultrasonic treatment, microwave treatment and other methods can increase the hydrolysis rate of sludge and improve the anaerobic digestion performance of sludge. Sludge anaerobic digestion technology will be a mainstream direction in the future.

(2) Aerobic fermentation technology route based on land use
Aerobic fermentation has high efficiency, relatively short stabilization time, reduced moisture content and sterilization. At the same time, the finished sludge is mainly used to repair saline-alkali land, urban greening, garbage dump coverage, and construction, so as to realize the organic matter in the sludge and Efficient use of nutrient elements, less equipment investment and convenient operation and management.

However, at present, aerobic composting still has problems such as net energy expenditure. At the same time, there is a lack of theoretical research on control factors such as reasonable ventilation and C/N in different stages. Traditional slab or trough composting covers a large area and the fermented products are polluted by heavy metals, making it difficult to develop aerobic fermentation technology in my country.
In the future, the sludge aerobic fermentation project can adopt an efficient, fast, stable, and intensive design and operation mode, which can achieve a significant reduction in the area; research shows that the proportion of heavy metals in urban domestic sludge exceeds the standard by about 5%, which is a pollution risk Smaller. This technology has great application prospects in relatively underdeveloped areas.

(3) Sludge drying-incineration technical route
Sludge drying and incineration are the most harmless, but the equipment investment and operating costs are high, and the flue gas pollution produced by incineration is serious. A complete flue gas treatment system needs to be established, which also increases the cost of sludge treatment. Therefore, the dry incineration process is generally suitable for areas with tight land use and developed economies.
At this stage, when the technology of anaerobic digestion and aerobic fermentation of sludge in our country is not mature, the drying and incineration of sludge may increase in a certain period, especially the method of co-incineration in industrial kilns.

(4) Technical route of sludge drying treatment based on building materials utilization
The high-dry dehydration process can reduce the sludge moisture content to 10%. And most building materials companies have sufficient waste heat and waste heat, such as kiln waste heat and flue gas in brick and tile factories. Using waste heat to dry sludge is a popular research direction in recent years. Treat waste with waste and dry sludge at the lowest cost to achieve the goal of substantial reduction. The dried sludge is mixed into building materials in a certain proportion as raw materials to realize resource utilization.

Sludge disposal refers to the disposal of treated sludge in the natural environment (ground, underground, water) or reuse, which can achieve long-term stability and the ultimate consumption method without adverse effects on the ecological environment. The main sludge disposal methods in my country currently include sanitary landfill, incineration, land utilization, and building materials utilization.

In 2009-2011, under the leadership of the Ministry of Housing and Urban-Rural Development, a batch of urban sewage treatment plant sludge treatment and disposal standards was compiled and issued, of which the “GB/T23484-2009 Urban Sewage Treatment Plant Sludge Disposal Classification” clearly provided four categories and a total of 11 items Disposal routes, corresponding to these disposal routes, issued (extended) a series of mud quality standards.

Among the 11 disposal routes in the above four categories, the three routes of separate landfill, production of lightweight aggregates, and fuel utilization (combined burning in power plants) do not yet have specific corresponding mud quality standards. There are objective policy risks and should be considered technically There are obstacles or lack of conditions for large-scale use in China. In practical applications, the two routes of brick making and separate incineration have basically not been adopted due to economic and environmental reasons. Mixed landfill (including the use of covering soil) is frequently eliminated as the resources of the landfill are gradually depleted. Some insiders suggest that the remaining five routes (landscaping, soil improvement, agricultural use, cement production, and mixed burning of garbage) should be selected in the following order according to the level of environmental protection requirements:

S.N. Item Range Details Standards
1 Sludge land use Landscaping Substrate material or fertilizer raw material for construction and maintenance of urban green space system or suburban forest land GB/T23486-2009、CJ/T362-2011
Land improvement Soil improvement materials for saline land, sandy land and abandoned mines GB/T24600-2009
Agricultural Agricultural fertilizer or farmland soil improvement materials GB4284-1984、CJ/T309-2009
2 Sludge landfill Separate landfill Landfill disposal in a landfill dedicated to landfill sludge There is no corresponding mud quality standard
Mixed landfill Mixed landfill in municipal solid waste landfills (including utilization of landfill covering materials) GB/T23485-2009
3 Utilization of sludge building materials Cement Some raw materials or additives for cement CJ/T314-2009
Brick making Some raw materials for making bricks GB/T25031-2021
Lightweight Aggregate Some raw materials for making lightweight aggregates (ceramsite, etc.) There is no corresponding mud quality standard
4 Sludge incineration Burn separately Special sludge incinerator for incineration GB/T24602-2009
Incineration mixed with garbage Incinerate with domestic waste There is no corresponding mud quality standard
Sludge fuel utilization Used as fuel in industrial incinerators or incinerators in thermal power plants There is no corresponding mud quality standard

(1) When the mud quality meets the requirements of GB 4284-1984 and CJ/T309-2009, and there is enough farmland for consumption, the agricultural disposal method of sludge is preferred;
(2) When the mud quality does not meet the above conditions (1) but meets the requirements of GB/T 23486-2009 and CJ/T362-2011, and there is enough green land (or woodland) for consumption, use sludge landscaping disposal method;
(3) When the mud quality does not meet the above conditions (1) and (2) but meets the requirements of the GB/T 24600-2009 indicators, and there are sufficient saline-alkali land, sandy land and abandoned mines waiting to be repaired for land use Disposal method of sludge soil improvement;
(4) When the mud quality does not meet the above conditions (1), (2), (3), or meets the requirements of various indicators in GB/T 24600-2009 but does not have enough land for consumption to be repaired and has a waste incineration plant At the same time, when the mixed burning can meet the requirements of GB18485-2014, the mixed burning with garbage disposal method shall be adopted;
(5) When the mud quality does not meet the above conditions (1) and (2), and the cement kiln resources are not available for the land to be repaired and the waste incineration plant, the cement kiln co-processing method is adopted; because the cement kiln Resources are extremely limited, and many central cities reserve them as hazardous waste and emergency solid waste disposal resources, so it is difficult to use them as a long-term means of large-scale sludge disposal.

In recent years, with the acceleration of domestic manufacturing upgrades, digital factories are quietly changing the traditional manufacturing methods of production, and promoting the development of the manufacturing industry to a high degree of digitalization and intelligence.

As a traditional “two high and one capital” (high energy consumption, high pollution, resource consumption) industry, the cement industry has been an eternal mission in the development of the industry to achieve more effective use of resources through technological upgrading from the moment of its birth.

Since the birth of the new dry cement (precalcined kiln) production process in the 1970s, it has become the most mature method of cement production with the highest resource utilization rate and the lowest production cost. Today, after 50 years of development, the precalciner kiln technology has been continuously improved through continuous technological improvements, and the energy efficiency has already exceeded the dust of the “predecessors” such as shaft kilns, wet kilns, and dry rotary kilns.
However, with the continuous deepening of the understanding of the production process, relying solely on the improvement of the equipment level, the improvement of the new dry cement resource utilization potential is facing a bottleneck. In this context, digital production methods have attracted the attention of the industry, and many experts and leaders of large enterprises in the industry believe that they are the “door” to open the future sustainable development of cement and the “key” to realize an epoch-making change in cement production technology.

In recent years, under the wave of digitalization, the domestic cement industry has also accelerated the pace of digital transformation. Thanks to this, the production efficiency and anti-risk ability of cement enterprises have been comprehensively improved. Public reports show that digital transformation covers all aspects of the company including production, sales, supply, transportation and daily management, creating conditions for companies to effectively respond to changes in the external environment. Especially during the epidemic, the needs of remote office, video conferencing and other mobile office scenarios were well met. Employees can work flexibly anytime and anywhere via the Internet.

On June 6, 2019, the Ministry of Industry and Information Technology issued four 5G commercial licenses, marking my country’s official entry into the 5G commercial era. The wave of digitalization is setting off a profound change in the cement industry. The use of 5G, big data, artificial intelligence and other technologies to empower cement companies and realize the digital transformation of the industry is a general trend.

With the development and progress of society, industry, and technology, after many years of enjoying the benefits of plastic functionality and economy, mankind has now come to the stage of emphasizing higher standards of health, safety and recycling. We have only one earth, and every country and every individual should start from now and from me.

As the largest developing country in the world, China is actively fulfilling its responsibilities as a major country and doing its utmost to achieve a balance of functionality, economy, health and safety, and cyclicality. If this is done well, China will truly achieve a leading role commensurate with its own conditions and status.

On the other hand, China’s plastic pollution control work cannot surpass its own development stage. Only efforts that are in line with national conditions and are committed to balancing functionality, economy, health and safety, and cyclicality will not float in the air too idealistically, and truly achieve results.

China’s efforts in plastic pollution control will have far-reaching impact. At present, the EU has been actively promoting international cooperation in plastics governance, hoping to play a leading role at the international level, promote the conclusion of a global plastics agreement, and promote the EU’s methods in the field of plastic recycling economy. Japan also expects to spread its technology, innovation, and environmental infrastructure on plastics treatment to the world. As the world’s largest country in the production and consumption of plastics, China will not only solve its own problems, but will also play an irreplaceable role in the global plastic governance cooperation.

On the morning of September 4, 2020, Luoyang Building Materials Architectural Design and Research Institute and the “Ant Dream” platform and the strategic cooperation signing and licensing ceremony of Guangdong Ant Dream Technology Co., Ltd. were held in Luoyang, Henan. Niu Huamin, Deputy Dean of Luoyang Building Materials Architectural Design and Research Institute, Lin Xunhuang, Chairman of Guangdong Ant Dream Technology Co., Ltd., Director Liu Jianyong, and Deputy General Manager Zhang Chunhui attended the signing ceremony. Vice President Niu Huamin and Chairman Lin Xunhuang signed a strategic cooperation agreement on behalf of both parties.

Guangdong Ant Dream Technology Co., Ltd. was established in April 2019. The Ant Dream platform takes “altruism” as its entry point, embraces sharing and symbiosis as its business philosophy, and takes “change”, “cooperation”, “creation” and “promotion” as four steps The path, through projectization, dataization, and standardization, promotes the transformation of the four mechanisms of human relations, transaction methods, value distribution, education and training, and realizes the four goals of resource convergence, interconnection of all people, sunny operation, and technology realization. Upstream and downstream enterprises and individuals provide “energy-saving scenarios” construction services.

Join hands to build, dreams come true; ants are small, dreams come true. Luoyang Building Materials Architectural Design and Research Institute and the founder of the “Ant Dream” platform have reached a consensus on strategic cooperation after many exchanges. At the signing ceremony, Niu Huamin, deputy dean of Luoyang Building Materials Architectural Design and Research Institute, accepted the “Ant Dream Partner” plaque awarded by Lin Xunhuang, chairman of Guangdong Ant Dream Technology Co., Ltd. on behalf of the institute. This signing not only marks the establishment of a long-term and stable strategic cooperative relationship between the two parties, but also provides assistance for the rapid and sustainable development of Luoyang Building Materials Architectural Design and Research Institute in the future. The two parties will carry out in-depth cooperation in the fields of ultra-low emission of cement production lines, optimization of building materials production technology, and development of new building materials products to provide a full range of services for cement companies to achieve the goal of “zero investment, zero risk, and high added value”. The two parties will also develop together, work together to create cement digitalization and intelligence, and provide the most cutting-edge technical support and technical services for domestic and foreign cement companies. At the same time, the two parties will also conduct in-depth research and cooperation in energy and environmental protection fields such as household waste, biomass, sludge, and oil sludge.

1. Based on multiple environmental elements of water, gas, soil, and solid waste, a total element system promotes the prevention and control of solid waste pollution

Emphasize “Take waste to treat waste and turn waste into treasure”, from the perspective of “three wastes” coordinated governance, a full-element system promotes the prevention and control of solid waste pollution, and solves the long-term problem of “recycling and uneconomical” that has long been excessively high corporate costs and market-oriented operations. Dilemma. Relevant scientific research units and solid waste generation, comprehensive utilization, and disposal units have carried out joint research on comprehensive pollution diagnosis, process optimization, and multi-factor coordinated management, and coordinated solutions to the recycling of wastewater, exhaust gas, waste heat, steam, and sludge during the disposal process , To realize all-element intelligent environmental management from planning and design, construction, production and operation to intelligent monitoring, intelligent management, and intelligent emergency response.

2. Based on the key points, difficulties, and pain points, establish a market-oriented multi-subject and multi-cooperative co-governance system

First of all, focus on key industries, carry out basic research on the comprehensive utilization of red mud, tailings, medical waste and other key products and transform technological achievements, highlighting precision pollution control, scientific pollution control, and pollution control according to law.
Second, strengthen demand orientation, strengthen guidance and assistance to local governments, and effectively solve the plight of local governments and enterprises that they are afraid of central environmental inspections but “have ideas but can’t help them.”

Finally, highlight co-governance and sharing. First, strengthen resource coupling, raw material complementation, and ecological links between related industries, and realize the transition from “single governance” to “comprehensive utilization”; second, strengthen regional coordination and abandon regional “administrative management”. Establish the concept of “regional co-governance”, and coordinate to solve the pain points of “no land available” in big cities and “not enough food” in the disposal facilities of surrounding cities; third, learn from the experience of the Yangtze River water ecological protection compensation pilot program, highlighting operability and appraisal, Based on the results of the grading assessment, establish a market-oriented horizontal compensation mechanism for waste transfer and disposal across regions according to local conditions; fourth, benefit the public to increase public participation, build public facilities around the waste incineration plant, provide preferential electricity prices, and solve the “neighbor avoidance” effect”.

1. More attention is paid to end disposal of recycling, and less attention is paid to the whole-process governance of the whole industry

Regardless of policy, technology, or market-oriented solid waste disposal in China, there are many processes focused on disposal, and there are few issues based on overall industry considerations.
From a policy perspective, the state provides fund subsidies for enterprises dismantling waste electronic and electrical appliances, but the fund revenue and expenditure are not balanced, the policy effect is to be evaluated, and the scope of implementation needs to be expanded.
From a practical point of view, taking the construction of a waste-free city as an example, various places have launched waste incineration and landfill plants in order to break the “garbage siege”, but the progress of the “two networks” of renewable resource recycling network and garbage classification and sanitation network has been slow, and urban construction only focuses on city appearance “Face” is beautiful, but the land planning for garbage sorting and storage related to urban “detoxification and beauty” is constantly shrinking.
On the whole, there is more “verbal attention” to source reduction, cleaner production and circular economy, and less “practical actions”, and most of them still focus on end-point pollution control.

2. A single environmental element pays more attention to it, and a water-based solid waste multi-element system pays less attention

From the perspective of environmental factors, the prevention and control of solid waste pollution involves multiple factors such as air, water, soil, and solid waste, which are interrelated and indivisible. In the past, there were usually many concerns about a single element, which led to the prevention and control of solid waste pollution “a symptom but not a root cause.”

Take the protection and restoration of the Yangtze River as an example. Pollution problems are complex and intertwined. Water pollution is manifested in the water, but the roots are “on the shore and in the water.” The heavy chemical industry in the Yangtze River Basin is intensive. According to the statistics of relevant departments of the provinces and cities along the Yangtze River Economic Belt, a total of 16,000 chemical industry projects have been added to the Yangtze River Economic Belt from 2007 to 2017, of which 1/4 are located within 5 kilometers of the coastline. There are 62 chemical parks along the Yangtze River, and more than 250 types of hazardous chemicals are produced and transported. Solid waste and hazardous waste have not been effectively disposed of. In some areas, smelting residues and domestic garbage are piled up in the open air, and anti-seepage treatment is not in place. The safety risk of tailings ponds is high, which seriously threatens the ecological environment of the Yangtze River.

3. More attention is paid to normalized pollution prevention, but less attention is paid to emergency response and long-term collaborative management

From the perspective of normalized management, various localities have comprehensively considered factors such as the size of the local population and the number of medical institutions, the daily amount of medical waste generated and the treatment cost, etc., and have built centralized medical waste treatment facilities that basically meet the normalized management of the region. However, from the perspective of emergency management, the sudden new crown pneumonia epidemic has exposed China’s serious shortage of medical waste emergency disposal capabilities, the coordination of medical waste and hazardous waste, the coordination of fixed facilities and mobile equipment, and the poor co-processing of solid waste in adjacent areas.

Solid waste involves many industries and fields, covering industrial solid waste, agricultural and forestry waste, domestic waste, renewable resources, construction waste, hazardous waste, etc. China is a large solid waste producer in the world. The historical stockpile of solid waste has exceeded 60 billion tons, and the amount is increasing by about 10 billion tons per year.

Especially with the blowout development of online shopping and e-commerce, a large number of disposable packaging materials such as plastics, papers, and fillers have increased sharply, which has brought tremendous pressure to the urban and rural environment.
Solid waste pollution has become a hot spot and focus of public concern, social concern, and government attention.

Compared with foreign countries, the level of solid waste utilization in China is still not high. In many cities, “garbage siege”, “white pollution”, solid waste “going up to the mountains and going to the countryside”, and illegal transfer and disposal of solid waste are still prominent. The end treatment model of “feet pain, medical treatment of the foot” urgently needs to identify the problem, grasp the crux, and research and propose a comprehensive solution.

At present, in the context of the national policy of “two prohibitions and one point to promote’no waste'”, that is, prohibiting foreign waste from entering, banning disposable plastics, promoting garbage classification and building a “waste-free city”, the prevention and control of solid waste pollution is facing new challenges. specialty:

One is the shift from importing solid waste and domestic recycling to focusing on domestic comprehensive utilization. The reform of the national solid waste import management system will accelerate the transformation of the comprehensive utilization of domestic resources.

The second is the transition from pollution end treatment to a full-process modern governance system, and the full-process governance model for source prevention and control, clean production and recycling will continue to be strengthened.

The third is the shift from simple recycling of a single industry to the coupled development of related industries, and the trend of collaborative development among enterprises, industries, and the whole society is becoming more and more obvious; the fourth is the transformation from traditional disposal models to new business models, such as Internet + recycling, green packaging, Wisdom and environmental protection.