Recently, there has been severe haze in north China, and the air in some places is seriously polluted. Will the coming heating season worsen smog? How to solve this problem? To this end, the economic daily spoke to fu Lin, an expert on urban energy planning and a professor at tsinghua university's school of architecture.

 

"" the arrival of the heating season does exacerbate smog. In northern China, the heating of coal-fired power plants accounts for about 40% of the central heating, while the rest is mainly coal-fired boilers. "Professor fu Lin said.

 

Of China's total energy consumption, about 2.5 billion to 3 billion tons of standard coal are consumed annually, of which one tenth is used for heating. Notably, nearly half of the more than 200 million tons were incinerated, with no stringent emission reduction measures, fu said. "Central heating has three characteristics: time concentration, space concentration and inadequate measures to control pollution from small and scattered coal-fired boilers. The emissions from burning one tonne of coal from small coal-fired boilers are equivalent to the emissions from burning 10 tonnes of coal from a large power plant.

 

How to solve this problem? Beijing, tianjin, lanzhou and urumqi have been pushed aside and some cities are following suit. Why didn't it spread quickly? There are two main reasons. One is the shortage of resources. In winter, many northern cities are short of natural gas. The second is the high cost. The price of natural gas is 3 to 4 yuan per cubic meter. In particular, he notes that natural gas, once considered clean energy, has been found to produce nitrogen oxides after burning, making it a major source of smog. Therefore, "replacing coal with gas" cannot fundamentally solve the smog problem.

 

One way, he argues, is to replace coal with industrial waste heat. After investigation, it is found that a large amount of waste heat is discharged from thermal power plants. If used, it can save energy and reduce emissions and realize recycling economy, and can completely replace coal heating.

 

There are two main problems in using industrial waste heat for heating. Is it worth it? The second is how to transmit to thousands of households over a long distance. 'most of my domestic coal is used to generate electricity,' Mr. Fu said. In northern China, the residual heat of power plants is about 500 million tons of standard coal, while heating needs 200 million tons of standard coal. Solve the second problem basically depends on heat net, because the temperature of waste heat is not high, be in 20 degrees Celsius to 40 degrees Celsius, and the quantity of heat that heating needs is 60 70 degrees Celsius more, must raise temperature, through heat pump technology, collect quantity of heat up, achieve usable temperature. Second, power plants are usually located in remote areas. How to transfer heat to cities is the key to improve the efficiency of heat transfer.

 

In order to solve this technical problem, the scientific research team led by him worked hard and achieved the invention result "centralized heating technology based on absorption heat transfer", which solved the problem of heat shortage and heat network transportation bottleneck, and realized the system heating capacity increase by more than 30%, heat energy reduction by more than 40%, and heat network transportation capacity increase by 50%.

 

"This achievement was awarded the second prize in 2013 for the national technological invention, which can be used to realize the conveyance length of 300 km from the heat source to the city in plain areas. That is to say, if the center of the city is drawn with a radius of 300 kilometers, the city's heating can be solved by waste heat recovery." Currently, the country has proposed the integration strategy of Beijing, tianjin and hebei, and there are many power plants in hebei, which can contribute to solving the smog through heat supply integration, fu said. Using the technology, which could completely replace coal-fired heating, is cheaper than using natural gas.

 

At present, this achievement has been promoted and applied in shanxi, Inner Mongolia, Beijing and other places, and has achieved remarkable economic and social benefits. "This year is the fifth heating season for datong city in Shanxi Province to promote the technology. Taiyuan is also promoting the technology, and cities such as shijiazhuang, jinan and yinchuan have been included in the plan," he told reporters. It is hoped that this innovative achievement will be promoted as soon as possible in northern China to provide solutions for haze control.