Nuclear heating from the nuclear power unit second circuit to extract steam as a heat source, through the first station of the plant heat exchange, off-site heating enterprise heatexchange station for multi-level heat exchange, and finally through the municipal heating pipe network will be transferred heat to the end user. Winter has arrived, many places in the country have been heating more than half a month. Unlike in previous years, this year’s heating has a “new pattern” – nuclear heating.
Nuclear power heating, in northern Europe, Russia and other places have more than 40 years of mature operation experience, nuclear combined heat and power supply of pressurized water reactor units cumulatively safe operation of 1000 years, while in the domestic, nuclear energy heating is also brewing for many years, and the relevant departments of the state actively support, but there has been no substantive breakthrough.
Recently, the “National Energy Nuclear Energy Heating Commercial Demonstration Project” was unveiled at Haiyang Nuclear Power Plant, opening a new situation in china’s multi-application of nuclear power, with a milestone significance.
Science and Technology Daily reporteron on nuclear energy heating landing time, safety and technical economy and many other public concerns interviewed a number of relevant people.
Water-to-channel technology advances lead to an expanded heating radius
“It’s a water-to-water thing. “Shandong Nuclear Power Chairman Wu Li said that nuclear power heating in the brewing for many years, this year’s heating season in due course.
On the one hand, the heating radius brought about by technological progress is expanded.
The latest version of the Regulations on Environmental Radiation Protection for Nuclear Power Plant, which came into effect on September 1, 2011, clearly stipulates that the boundary of non-residential areas with permanent residents shall not be less than 500 meters from the reactor;
This red line defines the shortest radius within the reach of nuclear energy for heating. According to Wu, by insulation technology, materials and other restrictions, the previous heating distance can not be too far, more than 10 kilometers is usually not reliable, and with technological progress, long-distance heat transfer has become more and more feasible, there are many domestic success stories, such as ancient long-distance loss (more than 40 kilometers), long loss (67 kilometers) and so on. Some long-distance heat transfer projects already under construction can reach 70 km.
“Nuclear long-range heat transfer is not technically limited. Wu said, combined with large temperature difference technology, absorbent heat pump technology, insulation material selection optimization, relay pumping station and other new technology applications, heat transmission distance can exceed 100 kilometers. And Haiyang nuclear power plant from Yantai, Weihai, Qingdao is exactly about 100 kilometers each, so the heating radius can cover smoke, green, Wei and so on.
He revealed that the heating area of 700,000 square meters, the future Haiyang nuclear power plant 1, 2 units after the transformation, a single unit in 2023 with a maximum heating capacity of 30 million square meters, according to the two units for each other’s backup calculation, planning in 2023 to achieve heating coverage around the plant site 60 kilometers, an area of 30 million square meters.
The emergence of nuclear power residual heat generation coal is a logical chapter
On the other hand, it is the development trend of green low-carbon.
In the past, the residual heat utilization of nuclear power plants was limited to self-use in the site. Reporters visited in the northern heating area of the existing nuclear power plants, such as Liaoning Red River nuclear power plant, Xu Dabao nuclear power plant, Jiangsu Tianwan nuclear power plant, including last year’s Unit 1, 2 into the Haiyang nuclear power plant, nuclear power residual heating plant winter heating, has long been nothing new.
“At the end of the day, there are limits to the thermal efficiency of thermal power plants, which cannot reach 100 percent. Zhang Zhen, an engineer in Shandong Nuclear Power Design Management Office, explained, “At present, the thermal efficiency of coal-fired power units has been raised to more than 50%, while nuclear power is less than 40%.” This means that there is a lot of residual heat generated, ‘you use it or not, it’s there’. “
For a long time, the haze has almost become the northern region heating season “standard”, boring and helpless. After the efforts of “coal-to-electricity” and “coal-to-gas” have shown results in recent years, it is logical that people will invest alternative heat sources for coal-fired heating into the same clean nuclear power.
“Further by insulation technology and equipment, extended heating coverage, nuclear energy heating came into being.” Wu said.
Safe and safe, only heat exchange, no water contact.
Common coal power plant drying tower, nuclear power plant drainage, is the export of residual heat. And the drainage port of nuclear power plant is only water to drain the residual heat, water is in the closed pipe, so only heat exchange, no contact with water, will not produce radiation. What’s more, because the temperature of the plant’s drains is slightly higher than the sea temperature, there are plenty of fish that gather nearby in winter.
The safety of nuclear heating, in fact, can be obtained from the aforementioned nuclear power plant self-heating can be obtained by side evidence – they know best that this is not safe.
For this public most concerned about the issue, Wu said from the technical level: “Nuclear heating is based on the existing unit power generation on the basis of local technical transformation.” Power generation is still the main business, heating is only a by-product. “
Nuclear heating is from the nuclear power unit second circuit to extract steam as a heat source, through the first station of the plant heat exchange, the out-of-plant heating enterprise heating station for multi-level heat exchange, and finally through the municipal heating pipe network to transfer heat to the end user. Throughout the process, in fact, only occurred two major steps of steam heating water and water heating water, nuclear power plant and heating users set up five circuits to isolate. There is only heat exchange between each circuit, no contact with water, and no radioactivity. The hot water in the user’s heating pipe is only closed in the small area, isolated from the layers of the nuclear power plant, very safe.
In addition, there are multiple monitoring tools in the plant to detect any minor anomalies. So nuclear heating is absolutely reliable and safe.
Multi-party win-win economy comparable to large-scale coal-electric cogeneration
“We have calculated that cogeneration in nuclear power plants can be economically comparable to cogeneration in large coal-fired power plants. “Wu put son with “residents with warm prices do not increase, the government’s financial burden does not increase, thermal company interests are not damaged, nuclear power enterprises to contribute to the operation, ecological and environmental protection benefits greatly improved” to sum up the demonstration project.
Reporters in the local Fengyuan thermal company “nuclear heating first station” to see that the original 65 tons of coal-fired boilerhas has stopped operation. Fengyuan thermal chairman Zhao Xin said that in the past, coal-fired boiler heating produces a lot of noise, the need for more operators. Now the heat exchange station can be unattended, saving labor costs.
Zhao Xin said that the first phase of the demonstration project to achieve 700,000 square meters of nuclear energy heating, the most intuitive effect is Fengcheng National Tourism Resort around the Fengyuan thermal chimneys do not smoke. If 200 million square meters of nuclear heating can be achieved in the future, it will reduce coal burning by 6.6 million tons per year, reducing carbon dioxide emissions by about 20 million tons and nitrogen oxides by 103,000 tons.
How to achieve such a “multi-party win-win”? Wu said that nuclear power plants have traditionally been simple to generate electricity, thermal energy utilization efficiency is relatively low, the comprehensive use of nuclear energy, but can improve the thermal efficiency of nuclear power plants. He estimated that in the future, if the heating area is expanded to the surrounding 4.5 million square meters area, the heat efficiency of the Haiyang nuclear power plant can be increased from the existing 36.69 percent to 39.94 percent.
Qian Zhimin, chairman of the National Electric Investment Bank, believes that nuclear power should be based on nuclear power generation, nuclear energy heating, desalination, energy storage and light storage, hydrogen energy and other multi-energy complementary, joint and efficient operation, to achieve nuclear power to nuclear energy expansion, single nuclear energy to multi-energy comprehensive utilization and expansion.